As a WMG subpage, all spoilers are unmarked as per policy. You Have Been Warned.
Whenever the Skyranger is on-route to or from a mission you are unable to issue commands at base because you are not at base you are flying. This explains why commutation from Bradford are transmitted over radio rather then in person. This might be an explanation why you can only have one Skyranger as there is only one of you.
- Alternately, you aren't the pilot, as he reports in to Bradford at the beginning of each ground op. Of course, there's nothing stopping you from taking the navigator's seat and directing the squad on-site. That the Skyranger is capable of offering a similar aerial viewpoint to what's used in-game is just icing on the moist, low-lag communication cake; hell, Big Sky is even a fitting callsign for a commanding officer.
- While more likely than the Commander being Big Sky, he still addresses you as "Commander" over comms at the start of every mission, implying that you're not right next to him.
- This Troper finds it unlikely that MEC troopers speak like that when wearing their Base Augments while off duty. Everyone seems to have forgotten that Goliaths spoke in exactly the same way back in 1998 as MEC Troopers in XCOM do today, and yet Goliaths were a piloted mech suit with a normal human inside of it. In both cases, the out-of-universe reason for it is Rule of Cool and the in-universe reason probably has something to do with ease of unit identification or a need to amplify the voice to compensate for the human being stuck inside a walking metal coffin that will tend to retain sound.
- MELD can be used to bond organic tissue with mechanical parts. Floaters at least would likely use some (supported by the fact that Heavy Floaters drop some MELD when killed), and most other organic aliens have some sort of cybernetic implant.
- It's likely that the Meld you find during the early game is supplies the aliens are bringing along to have it handy for the later stages of the invasion, so they can perform conversions on site. Considering how quickly XCOM can learn to apply it, it's likely that it was made as a way of performing genetic modifications or cybernetic augmentation on the troops on the field quickly and efficiently.
- Genetics don't work that way. If a person has skin cancer on their arm (a genetic modification via solar radiation) their children won't be born with skin cancer on the same point on their arm. In order for a genetic trait to be inheritable, the Sperm or Eggs of a human must be modified, not, say, the muscle tissue of an arm or a leg.
- And who says that Meld Gene mods are accurate enough to only target the affected area, and not change the entire body, including sperm and eggs? After all, the would-be Gene Trooper is held in a tank full of Meld...
- The fact that those gene mods only affect the targeted areas means that the genetic modification is likely not performed on every cell of the body, but rather only on the targeted areas.
Look at that face◊ and tell me he's not!
- That's about the most awkward looking picture you could have possibly found of Alton Brown... but then my science teacher looks exactly like Alton Brown, so there maybe some truth to this...
- Pretty self-explanatory.
- The Ethereals refer seemingly to themselves as the "greatest failure of the Ethereal Ones". They explain that their physical forms are too weak to be sustainable. Humans, being both psionically potent and physically durable, represent their greatest hope - hence their intense disappointment at failures of the squad on the final mission. It would seem the Ethereals themselves may be, as their name implies, bodiless psionic entities that move between hosts. Realizing their current forms are too weak, they have been attempting to engineer or discover a new host species, with humanity as their brightest new candidates.
- Pretty much confirmed by XCOM: The Bureau
- Alternatively, it's possible the Ethereals' bodies are their original ones, but they may still be planning to "move out" into human bodies after all their other candidates proved unsatisfactory. Either way, what they imply "lies ahead" could be the imminent Ethereal mass-possession, or it could be something else.
- Snakemen were oddly missing from the remake. There was also only one addition to the roster of new alien species. The Thin Men. Which are reptilian in origin. Thin Men are literally genetically engineered Snakemen. There's where they are. Now to go prove that the cafeteria food in XCOM headquarters is actually celatids and silacoids.
- Confirmed.
- The cafeteria food has been confirmed? Jinkies!
- Cyberdisk autopsy reveals that they contain silicon-based organic components. It seems the Ethereals found plain old silacoids unworthy...
- Confirmed.
- As did all the other members of his/her crew. S/he IS the most powerful psychic ever to exist of all time, afterall. Whose to say s/he couldn't shield them all from the cataclysmic explosion and become a god?
- Maybe it's because I ship my two psychic colonels together and they were the only survivors... Then again, battle hardened psychic space lesbians is a great ship.
- That may be the most awesome ship this troper has ever heard of.
- The Volunteer surviving may be a WMG but the rest of the crew surviving isn't. The cutscene clearly shows them flying away as the ship blows up.
- The Volenteer actually pushes at least two of his/her team onto the Skyranger with their mind...
- Confirmed with this tweet from Jake Solomon, the Lead Designer of XCOM Enemy Unknown.
- There's a Stargate crossover in there to be written.
- This troper heard of such fanfic's existence (Based on classic X-Com though) and can recommend it to everyone who likes either franchise.
- Considering that the alien temple ship was suppoedly forming a black hole and it exploded instead...where did the energy go? It can't be destroyed, only converted...such as shoving a psionic being into the next realm.
- I think that they did survive. The "package" that the pilot references is the Volunteer, the rest of the squad makes it back to the Skyranger just in time. But then I'm an optimist.
- Their death wouldn't make sense from a narrative standpoint, as it would render the scene where the Volunteer telekinetically pushes them out through the closing door of the final chamber kinda pointless.
- Seems pretty obvious that they made it out...they got shoved telekinetically and were possibly pushed psionically back to the Skyranger, it took off with everyone on board.
- Their death wouldn't make sense from a narrative standpoint, as it would render the scene where the Volunteer telekinetically pushes them out through the closing door of the final chamber kinda pointless.
- The Volunteer (The New One) represents XCOM: Enemy Unknown.
- The "Failures" are all metaphors for the previous games in the franchise to try and live up to the original game's success. Some got farther then others, but in the end, none of them reached it's level of quality.
- Mutons are Enforcer
- Chrysalids are Terror From The Deep
- Sectoids are the FPS
- Sectopods are Interceptor
- The Thin Men are Apocalypse
- The Ethereals, the best of them all, represent the original game.
- They have been looking for a true success for years, and they have found it in the form of....The New One. The only one to reach such power and such success.
- Drones could be The Bureau, looking a little better than the original FPS (having a few more tricks up their sleeve than Outsiders/Sectoids such as repairing other mechanical units), but still ending up So Okay, It's Average at best.
- Wouldn't Outsiders be the equivalent of the FPS? Outsiders are inconsequential, forgotten shortly after discovery, and ultimately nothing more than a lead to something bigger and better. Sectoids could represent various X-Com remakes and fan sequels—weak (lacking budget and veteran programmers) and cruel (hewing to older game design styles and presentation against all logic), but at least they've got the Gift (fan-love and creativity).
- Not to mention that the outsides are very similar in portrayal to the mechanical enemies in the fps, created a mechanical body from light and energy.
- EXALT could be any source of Executive Meddling in the series, as they appear to serve on the side of good (Giving life to the game and advertising it), but they just end up undermining the whole thing.
- Those are Square Enix games, XCOM is 2K. Besides we already got a triad member in the DLC.
- Somewhat true. One DLC mission involves rescuing a defecting Triad member who then joins your squad as a heavy.
- Those are Square Enix games, XCOM is 2K. Besides we already got a triad member in the DLC.
- Adds a minigame where the RED team fights an endless horde of aliens.
- Adds a council mission where you have to retrieve a fallen Space Core, much like the Skyrim Mod "Fall of the Space Core Vol. 1".
- Adds an council mission where you escort Gordon Freeman out of Black Mesa. He then joins as an assault-class character.
- What about one that adds Tanks as spawns from a new "Elite Chryssalid"?
- What Monoliths? No X-Com game had anything remotely similar.
- I think it's referring to the aliens from the earlier FPS videos.
- Alternatively, it's a cleverly-veiled reference to Laser Pumping.
- Or, there are several batteries in a clip, and each shot discharges the battery, which would explain the heavy damage the weapon does compared to the regular laser rifle.
- Another possibility is that the pump itself generates the charge for the next shot. Kinetic motion, like a windup flashlight
- OR the designers didn't bother to change the animations for the weapons.
- Or the people designing the games (or the lasers) thought it would be cool.
- Alternatively, your run of the mill Muton are just pumped full of over dose levels of sedatives (by human standards anyway) which dulls their blood lust to allow them to be at least semi-tactful during missions.
- Partially contradicted by the game- autopsy a Muton Elite and you'll learn that the Ethereals simply dump war doctrine and tactics directly into the Muton's mind. Berserkers being largely unchanged from their original state makes sense though.
- Jossed. The DLC, entitled Slingshot, will be set in China instead.
- Who says there will be only one DLC? TFTD would make an awesome sequel game though. But then again there's always Cydonia...
- To all outward appearances, the Council is a Reasonable Authority Figure working to thwart the alien invasion. But consider the following:
- They certainly give off the "creepy shadow organization" vibe.
- That trait is mandatory in every shadow council in any series. Just because they're odd doesn't mean they're mind controlled.
- The Council continuously drives the XCOM project to push humans to the limits of their abilities (and beyond), using technology recovered from the aliens.
- It's not the Council that encourages XCOM to evolve: they never ask you to do anything apart from the general goal of "stop the alien invasion" and occasionally escorting VIPs. Theoretically, you could do the game without upgrading weaponry a bit and only having one psi-soldier, and they'd be peachy if you were still winning. It's you that doesn't want to go up against Sectopods with regular firearms, like the Ethereals want you to.
- Most of the Council missions exclusively involve Thin Men.
- They're infiltrators. You're going to accomplish an objective. The aliens' infiltrator scouts alert the rest of the aliens to your activities, and they try to stop you. What does this even prove?
- The invasion tends to scale up staying always just one step ahead of XCOM.
- The Aliens are intentionally scaling up for XCOM specifically. They won't need the Council's updates on your progress; if certain aliens are getting trounced easily, send a stronger one. Plus, if the Council is keeping them appraised, why the hell did they send me to a terror mission when I hadn't upgraded any armor or weapons and all I had in reserve were 5 squaddies?
- We never see the Council members' faces. (They could be cooperative humans, mind-controlled humans, or even Thin Men)
- The cooperative humans and Thin Men theories are Jossed, as the game over screen shows the spokesperson for the council being mind controlled by a Sectoid Commander. It doesn't say that they've only been mind controlled since the project was abandoned, however, so the theory over all is still valid.
- If they're already mind controlled, what's the point of obviously mind controlling them an additional time?
- As stated in The Reveal, the Ethereals staged the invasion to uplift humanity and prepare them to fight the Greater-Scope Villain.
- Again, it doesn't mean that the Council is in on it.
- "Remember, we will be watching." (Who is "we", exactly?)
- The Council Members. Duh.
- They certainly give off the "creepy shadow organization" vibe.
- If XCOM succeeds in stopping the invasion, the Ethereals plan to use the uplifted humans in their army. If it fails, the Council pulls out and the aliens presumably subjugate humans as another of their failed attempts. Either way, the Council is actually working for the Ethereals, playing the good cop role and using the XCOM project to advance the Ethereals' agenda!
- Extremely unlikely. Apply Occam's Razor for a second. Sounds like a lot of conspiracy theories saying that all the governments are controlled by one body and whatnot.
- It turns out the Thin Men and Sectoids are looked down on by the Ethereals. If XCOM succeeds, they are freed from the Ethereals' rule. If XCOM fails, they can take credit for a successful invasion, potentially gaining respect from the Ethereals.
- Sectoids are Grays
- Thin Men are Reptilians
- Chryssalids are Mantoids
- Outsiders are possibly fifth dimensional/density energy beings
- Sectopods, Floaters and Mutons are the only ones that do not have a counterpart in the urban legends
- They may not have urban legend counterparts, but the Sectopods might be ATSTs, Floaters and Mutons might be The Borg and Klingons, respectively.
- Really? I saw Sectopods as ED209 from Robocop.
- They may not have urban legend counterparts, but the Sectopods might be ATSTs, Floaters and Mutons might be The Borg and Klingons, respectively.
- Etherals are Annunaki
- Is this really a WMG? It's pretty obvious what they were going for.
- Covered above
The Etherals were a race that the Reapers attacked and nearly wiped out, to the point where only a couple hundred thousand are still left. They spent the 50,000 years since then traveling the galaxy, trying to find a race that they could uplift that would have a chance at beating them. Because Humans Are Special in both Mass Effect and XCOM, they were the appropriate choice. And if Mass Effect has proven anything, people tend to ignore the existence of the Reapers until they were right on their doorstep, so the Etherals attacked Earth themselves, forcing Humanity to unite under the Council (The Human one) and forcing them to develop more advanced technologies preparing them for the Reapers down the road, not to mention causing Humanity to become much more militaristic with them under the assumption that all there is an empire of aliens out in space waiting to conquer them. When the Reapers eventually show up, Humans will be centuries or maybe even millenniums ahead of what they were expecting.
- This idea is GLORIOUSLY explored here
- Alternatively, the threat the Ethereals speak of is the Dark Voice
All of Torchwood went defunct by 2010. What else are a bunch of people savvy to that business behind the curtain going to do?
- And by the same token, the Americans (and possibly many of the others) are veterans of the Stargate Program.
Since the game doesn't actually tell you what the device's acronym stands for lets take guesses. My guess is:
Sight Correction and Optical Perception Enhancer
- Shot Calculation to Optimise Performance Equipment
- Silly Contraption Only for Popping 'eads.
- Self-Computing Optical Precision Enhancement
- Self Correction O Ptical eyepiece
- Some Creepy Old Pervert's Enabler
The XCOM recruits are supposed to be the best of the best, drawn from various military and special forces organizations from around the world. So why does it seem like they all graduated from the Imperial Stormtrooper Marksmanship Academy? My hypothesis is that the guns are so large, heavy, unwieldy, use such a high caliber, and have such an enormous kick, that it takes a while for the troops to "get their eye in," so to speak. Even the basic assault rifle looks like it must fire a .50 cal BMG round, or something even more ridiculous, and that's before you get to the real exotic stuff like lasers or plasma.
- Not to mention the fact that, yes, they're the best of the best, but, well...they're fighting ALIENS. You're telling me THAT isn't going to make their hands shake a LITTLE?
- On the rifles...the standard XCOM assault rifle (the X-9 I believe) has a MASSIVE barrel. Meaning, more than likely, its firing a huge round. .50 caliber perhaps...and as anyone who's seen the recoil from a Barret knows...well...
- Not to mention the fact that, yes, they're the best of the best, but, well...they're fighting ALIENS. You're telling me THAT isn't going to make their hands shake a LITTLE?
Now, why the XCOM HQ doesn't have a firing range for your troops to practice...
- This is actually a Reality Is Unrealistic moment. In real combat, the vast majority of shots miss.
- Hence the necessity for high rates of fire.
- alternatively, X-COM is a United Nations Operation. Which means the soldiers X-COM gets are not the best of the best so much as the absolute bottom of the barrel. This could explain a few other things, for instance why you get troops from all over the world, Why you can choose your base of operations from any continent on the planet, and why they use non-standard military ranks.
In Enemy Within's announcement trailer the Council Representative talks about "another force at work against us" before the feed cuts out. Very briefly this◊ symbol can be seen before the signal is lost.
- For those who don't know, the Cult of Sirius was a human organization in the original XCOM that believed that the aliens were actually harmless and key to humanity's enlightenment. Ironically enough, as of Enemy Unknown they might be right, given the Etherial's motives to uplift humanity.
- A big clue here is the expansion's name: "Enemy Within". While the developers have gone on record as saying the title comes using cybernetics and gene splicing derived from alien technology is literally being the enemy within, it's very likely there's a dual meaning to the title.
- Expect to fight human soldiers similarly equipped to XCOM's own forces on top of the alien invasion itself, similar to the war against Cerberus and the Reapers in Mass Effect 3. Because a war of this scale on one front was already easy enough.
- Jossed: The player will not encounter both EXALT operatives and aliens during the single-player campaign, although in multiplayer they can build teams with units from all three factions.
- Partly confirmed; there's an alien sympathist faction called EXALT that will try to undermine your operations, but they may or may not be related to the Cult of Sirius.
While The Bureau: XCOM Declassified is an alternate continuity game to XCOM: Enemy Unknown, there's no evidence denying that The Bureau still existed in the XCOM: Enemy Unknown continuity, but never actually combated aliens, like in The Bureau. When it was believed that there was no threat, the Bureau was thought to have been disbanded, but in reality, they still continued to thrive and seek out alien technology due to the discovery of Elerium in the 1960s. Now that aliens are properly invading Earth, they have come out of hiding and are now seeking to gather all the alien technology for their own.
- Actually, it seems like The Bureau is part of the Enemy Unknown/Within universe...researching Meld in Enemy Within gives a small bit of flavor text referencing "redacted files on a similar substance" made in the '60s.
- Enemy within suggests otherwise about EXALT's origins, implying the organization is quite old and ritualistic, considering the age of the recovered artefacts from their HQ.
- Alternatively, EXALT is part of The Bureau's resources and personnel gone rogue, picked up by some other party and repurposed to suit their needs, while the majority of the Bureau became XCOM.
At the end of The Bureau Asaru disappeared with "Its status, its location, and its intent are... unknown." In a twist he never left Earth and once again acts as the player character to help against the invasion.
- In XCOM 2, the Commander possesses extremely powerful psionic abilities after being downloaded into an Avatar body, and their psionic aura is the same light blue as Asaru's, instead of the deep purple used by psi troopers and Ethereals. The game explains all this as due to the Commander having had a microchip implanted into their brain that previously linked them into the alien psionic network, but the X-Com scientists explaining this may simply be misinformed. In the final mission, the Commander's Avatar seems to control their squad directly in the same manner that Asaru's host did throughout The Bureau. And the game repeatedly mentions how special and incredible the Commander is, without providing any background details as to why they're the greatest tactical asset either side has ever seen.
- The war against the Ethereals took place all the way back during the Age of Terra, with the the hostile first contact with alien life forever cemented humanity's distrust of xenos. The reverse engineered alien technology jump stating humanity's scientific knowledge and allowing for rapid technological advancement that eventually became the basis for the Dark Age of Technology and the creation of the Standard Template Construct (with laser and plasma weapons being some of the few designs that survived into the 41st Millennium). While X-COM eventually inspiring Malcador to create the Inquisition (The organization's ability to serve as the guardians of humanity operating outside the law, and the Ordo Xenos inspired by Dr. Vahlen's alien interrogations) and the Emperor to create the Adeptus Astartes (A small, elite, power armor wearing, genetically engineered, Super Soldiers that serves as the spear tip for the rest of the military during conflicts).
- The MEC troopers from Enemy Within are the earliest form of what would become Imperial Dreadnoughts – after seeing how effective they were against the aliens, the use of giant cybersuits to allow injured soldiers to keep fighting became standard.
- It gets worse. The Mutons and Floaters (both made out of the same species)? The Krork (IE, progenitor race of the Orks). Spread far and wide across the galaxy, a few planets harbouring them were conquered by the Ethereals, which led to these groups being "uplifted". The extensive modifications seen on both enemies have dessicated them, turning their skin from healthy green to leathery brown. Their asexual spore-based reproduction system made them incredibly easy to breed and clone in large numbers, and their natural bloodlust makes them excellent frontline soldiers. Plus, Plasma makes gudd dakka.
- Thin Men are heavily modified perversions of the Hrud, or possibly Slaan given their reptilian traits. Chryssalids are reverse-engineered from isolated Genestealer cults (or, again, the Hrud). Sectopods, Cyberdiscs and Drones are reverse engineered from Demiurg or possibly even Necron technology. There might not be an equivalent for the Sectoids, but its likely that they've been utterly exterminated and all knowledge of their existence lost by the time of the 41st Millennium.
- A guess would be "EXtremist Alien-Loving Terrorists".
- It stands for Exaltation, but X com assumes it's a acronym so they always spell it like EXALT.
- Alternatively, in the sequel the player might control a different faction, which doesn't have XCOM's alien technology at the start.
- Sorta confirmed: XCOM got Curb-Stomped before they could make any significant research
- Potentially confirmed. The available news about the sequel seems to indicate there's a human force working with the aliens called ADVENT. Seems likely this is what EXALT turned into after XCOM was obliterated.
- The destruction of the Temple Ship left behind a portal in Earth's orbit. A recon mission reveals that it leads to the Ethereals' HQ. An assault mission is sent, with XCOM bringing along a strong psionic to hack into the Ethereals' information network/Hive Mind to gather more intel. The gathered intel reveals the Ethereals are prepping for a greater threat and reveals the location of a member/unit from this greater threat separated from the rest. XCOM deploys there to gather more intel and/or try to secure an alliance, but finds out that they're hostile and stronger than anything previously encountered. XCOM defeats them with great difficulty, but is now left with the prospect of battling an enemy even greater than the Ethereals.
- Alternately, Asaru reveals himself and offers to help XCOM defeat his kin at the source. XCOM doesn't trust him at first, but accept his offer after his role in stopping the previous alien invasion is revealed. The rest continues as above, skipping the recon mission and the strong psionic requirement for the HQ Assault mission (since Asaru is tagging along). As a further Call-Back, Zudjari survivors may show up and help XCOM against the Ethereals or the greater threat.
- It's already been shown the Civilization franchise exists in the same universe as XCOM, and SMAC picks up where a Science Victory ends in Civilization. The Ethereals know the Usurpers are trying to achieve godhood through exploiting Manifold Six, and fear they will conquer all other races if not stopped. They've chosen to fight fire with fire and combat transcendence with psychic powers.
An elite organization dedicated to specific strikes, which employs technology far beyond the scope of any other army, and eventually uses incredible psionic powers which manifest via purple energy? Sound familiar?
- What XCOM refers to as "Meld" is actually the Firaxite that allows for the Brain Uploading of Supremacist civilizations, and Purist factions believe they are following in the footsteps of the XCOM project.
Really, the only question is whether the Ethereals were grooming Humanity to fight the Shadows, or given the 'Forced to Evolve' nature of the invasion, to fight the Vorlons.
XCOM IS SIMS!
It is common for people working long job watching evolving data on screen and communication through radio to banter with each other to kill some time. And that banter is the only thing the Covert Operative could pick up. The Covert Operative has confirmed that the banter comes from the EXALT HQ, but couldn't locate it. How would banter help locate the HQ you ask?
"Really, the dub for Sailor Moon is a train wreck. Bad acting, censorship, continuity errors, you name it! I'm glad I downloaded the subbed version. Say, I'll drive you to the restaurant after our shift, okay?" The technician at EXALT's HQ lives within driving distance of it, and doesn't speak Japanese (why else would he need to download a subbed version of a Japanese anime after watching a dub he called a train wreck?) Therefore, the EXALT's HQ is not located in Japan.
"The good thing about working this job is that it's well paid and in my home town, therefore I can go to my favorite sushi restaurant any time I want. The bad thing is that I had to go through annoying English classes just to get it." Any people born in an English speaking country like the UK, Canada, the USA or Australia would have already learned English long before taking a job at EXALT. The EXALT HQ is not in an English speaking country.
"You know what? I'd like to visit Brazil one day. I heard it's a pretty nice country that's very accepting of gays like me." The EXALT HQ is not in Brazil.
Simply, each scientist knows some basics on every scientific field and basic experiment standard operating procedures, and has a pretty good understanding of mathematics and computer use. On each project, the experts device experiments to understand thing, the non experts help set up the system, and after it has been performed, the lead scientists in the project give the ones not expert in the field relevant, boring, repetitive but easy calculations and computer work while they do the more interesting and specific stuff. But the ones doing the boring stuff know that when the next experiment is withing their field of study, the roles will be reversed, possibly leading to banter such as "I will have my revenge on you someday!" during experiments.
Psi snipers + Ghost Armor/Mimetic Skin = GhostAside from the ghost armor your snipers can't call nukes though
Humankind encountered some terrible threat beyond mortal comprehension, and to fight it, they develop the latent psychic abilities of certain rare individuals, performing one extreme experiment after another. The result was...the Ethereals. They failed, but just before the "greater threat" destroyed the Earth (or something), they were able to time travel back to a point well before the Greater Threat's emergence.
They then invaded the Earth of their past, the denizens of which assuming they were from another planet, in order to abduct more specimens to genetically and cybernetically enhance, and wound up with the Sectoids, who, again, failed to stop the threat. So the Ethereals went back in time again. Next came the Thin Men, then the Floaters, then the Mutons, and perhaps even the Chryssalids. Again and again their creations failed. The game takes place on the final cycle, when the Ethereals finally realize that Humans Are Special, letting them develop psionic powers themselves, and finally end up with the ideal psionic specimen.
That's why Zhang deflected, he realized that trying to Take Over the World during an Alien Invasion wasn't a good idea.
Think about it, read any old UFO story where the military miraculously shows up moments after a UFO crash. The whole point of the original X-COM's creation was to make the whole thing seem to be absurd and with the massive increase in tech they revived the propaganda campaign to basically make anyone reporting strange soldiers showing up at UFO crashes seem like kook talk.
Final mission, the most powerful Psionic on Earth, possibly in the universe, sacrifices themselves to save the planet from the exploding alien ship. Word of God says this doesn't kill them. They instead Ascendt To A Higher Plane Of Existence, becoming some sort of omnipresent force. Eons before the game, the aliens detect this force, but have no idea what it is, just that the universe needs to be ready to fight it. They build an army, research psionics, and invade Earth.
If they succeed, the final mission never happens, so the Volunteer never sacrifices themselves, undoing the Stable Time Loop and resulting in X Com 2.
We know from Word of God that Sectoids are by default cruel and cowardly, and they are, aside from Ethereals, the only alien species that possesses the Gift. And when XCOM soldiers use their own psionic powers, their voicelines seem very... enthusiastic. It's likely that using psionic powers gives the user a strong rush, and may make them feel omnipotent, which in a species bred and trained for the aggressive use of such powers like Sectoids would naturally translate in cruelty - but at the same time, certain uses of psionic powers can lead to other feelings, as we see in XCOM: Chimera Squad with Verge, a former Sectoid Commander who learned empathy by constantly being inside the minds of humans to control them.