That One Sidequest / Xenoblade Chronicles 2

• Every rare blade has a quest chain that must be completed to either receive the blade or unlock their power on the affinity chart, and the worst by far is commonly agreed to be Ursula’s. Her affinity chart is one of the most heavily integrated with her personal quest, and most people agree that if you want to use her, you might as well leave the last tier locked. Her quest neither requires completion of a difficult task nor continuous effort on the player’s part, but if you want to complete it, Ursula needs to be sent out on special mercenary missions so many times that you basically won’t be able to use her at all for nearly the entire length of the story. How long does it take? Assuming you're sending her out as often as possible with the best Blades to support her and speed things up, it takes 16 hours (real-time) to unlock her final tier.
• Another worthy mention is building Vess' Dumpling cooking skills. She must make 100 Dumplings, and the primary ingredients for them aren't the kind that are commonplace all over Alrest. The best place to farm Salty Soil, for instance, can possibly be made much harder to access once the mission "Farewell Good Friend" is completed, which spawns level 90 Drivers all over.
• A more commonplace example would be "Deal X Damage in one hit", especially for Healer blades. This is the only quota that cannot be filled through mercenary work, and it can be a difficult deal to deal damage in one strike.
• Included in the Expansion Pass Quest set is "Midnight Feast", where the player must gather various ingredients and experiment with them. Only one recipe works. Good luck figuring which one it is without looking it up, all the while wasting valuable food items!
• Getting 50,000 points in "Tiger! Tiger!" needed for Poppi's Affinity Chart is not an easy feat for those who are not good at the game. It requires a near-perfect run of having full health and have collected (and held on to) all of the ether crystals and treasure chests in the level, which is no walk in the park even on the easiest level (Level 1). The score also has to be obtained in a single go, which will result in a lot of runs consisting of trial-and-error in order to get it. Mercifully, it can be completed via Merc Missions instead, and Poppi's upgraded forms don't have this same requirement (meaning you can bypass it if you want to go solo QTπ on Tora as the playable character or on New Game Plus).
• Unlocking Perun's second tier in the Affinity Chart is major Guide Dang It! that has very vague details on what to do. You basically have to go around in every town and find a person with a trophy icon above them and do a mini-sidequest that will increase the level. There's one problem with this: not all of them add to the affinity count. Thankfully, if you get Perun late, the game will count any good deeds you already did, and some of the good deeds are repeatable, preventing her Affinity Chart from being Permanently Missable Content.
• Late in Godfrey's Blade Quest, you are required to find four civilians and get to them to safety during a monster attack in town. While the monsters themselves are marked on map and the quest bar, the civilians are not. This can force the player to run around all over the city until you run into them by accident.
• Get too far in Chapter 10 and the Superbosses and accompanying flunkies appear across Alrest. Nim and Perun have Affinity Quests in areas that get level 90+ enemy populations. Doing those quests gets... interesting, after that.
• The Challenge Mode battles are hard by design, and are required to complete the Affinity Charts for the DLC crossover Blades (Shulk, Fiora and Elma). But a few stand out as especially annoying or unbalanced, and would qualify for That One Boss if not for their being optional:
  • "Reinventing the Gogol". Required for Fiora's Affinity Chart, the match pits the party against waves of Gogol enemies. The main Lv. 150 boss, Immovable Heir Carlos, is hyped up as a successor to the infamous Territorial Rotbart and Immovable Gonzalez. He has insane Break resistance, making Driver Combos harder to pull off and effectively requiring you to have Tora with Poppi QTπ on your party. His "Feral Beat" art shackles all Drivers and eats up one segment of the Party Gauge. On top of that, his Venom Cloud attack inflicts Doom on all party members, which is an unavoidable insta-kill and is described under That One Attack. Finally, when enraged, Carlos is guaranteed to use the Wild Wave attack, which is designed to be a Total Party Kill and is difficult to avoid via natural evasion (and thus needs to be treated similarly to Venom Cloud).
  • "Cloud King's Revenge" is required for Elma's Affinity Chart and is a rematch against a souped-up Cloud Sea King Ken. Ken hits like a truck with his auto-attacks (which inflict Break) and "Rear Whip" back attack. His "Cloud Breath" art is easily his most annoying, as it inflicts massive party-wide damage, drains the entire Party Gauge if all hits connects, and summons legions of reinforcements that are sure to gang up on the aggroed Driver and tear them to pieces. His "Tentacle Storm" Art, like in the Unique Monster battle, also inflicts massive party-wide multi-hit damage and Blowdown on each hit. Fortunately, actually using Elma during the battle lets you use the reinforcements somewhat to your advantage; if you activate Overdrive and use an AoE Special like Mythra's Photon Edge, it's likely to kill most or all of the reinforcements and fill up your Party Gauge a significant amount, possibly even making up for the drain from Cloud Breath.
  • "Mk. VIII", required for Shulk's Affinity Chart, is a battle against robotic enemies. Wave 2 throws multiple Nitro Sovereigns and a Lv. 200 Strategizer Nitro at you, all of which will attempt to use their self-destruct move to end the match and kill the party. There are multiple ways to get around this, the most obvious of which are a Fire Blade Combo to seal self-destruct and/or making sure Shulk is out when the Strategizer uses the move so that you can avoid it with his Vision. The main boss, True Rosa, is mostly fair except for one move: she will summon three Minirosas that each lock a segment of the Party Gauge. While they don't have much health, she will do it over, and over, and over again, and the "Ultra Bang-Bang" summoning Art can't be interrupted with Driver Combos. This adds another level of Character Select Forcing, requiring a Dark Blade Combo to seal reinforcements; Dark is the hardest Blade Combo to pull off because of the rarity of the element, the lack of truly excellent Dark Blades aside from Elma, T-elos and a Dark-type Poppi QTπ, and the fact that it needs at least 2 of the same element in a row. Oh, and Bana and Muimui aren't piloting Rosa this time around, meaning the fight is completely humorless and there aren't even any funny lines to laugh at to make your repeated deaths less painful.
  • "Serious Showdown", required for Fiora's and Elma's Affinity Charts. A repeat of the infamous Jin and Malos Dual Boss from Chapter 7, with one key difference: instead of reducing one of the pair's health to half (which was already extremely difficult), you need to completely defeat both villains. Not even your now having access to Pyra, Mythra and Pneuma, nor the very small nerfs applied to Jin and Malos make up for this added difficulty. Oh, and they can undergo Elemental Awakening too.
  • By far the worst and most infamous Challenge Battle is "9th Imp. Armored Div.", required for Shulk's and Elma's Affinity Chart. The main boss is a Lv. 130 Ardainian Kurodil, an even more brutal version of an already difficult superboss, and it throws everything at you to make sure you can't do a thing to it. For starters, it constantly enrages (even from the start of the match) and inflicts enormous spike damage in its enraged state if you attack it, requiring the player to have some means of healing or defense against said damage. It's near-impossible to Break, making it hard to perform Driver Combos on it even with a maxed-out Tora. All its arts hit like a freight train, and on Bringer of Chaos difficulty they're also Rage Strikes that drain the Party Gauge. Like Immovable Heir Carlos, it also has a party-wide Doom attack (Murder Ray) and a flat-out Total Party Kill that is hard to avoid and makes it invincible (Ultra Annihilation Flare). And then there are the other waves of enemies that appear while you're fighting Kurodil: an Ardainian Sharper who will snipe at you to drain the Party Gauge, Ardainian Drages that also have Party Gauge-draining attacks, and Ardainian Musses that lock up the Gauge and, unlike the Minirosas, can take a beating. Some players believe that the fight on Bringer of Chaos crosses the line from "a challenge" to flat-out cheap and unfun.
  • "Elma Redux". Possibly tied with Ardainian Kurodil for the most infamous superboss, this battle is required to use Elma outside of the Land of Challenge. She starts the battle by summoning three Ghost Elmas that lock up the Party Gauge, and will continue to do so until you use a Dark Blade Combo to seal reinforcements (once again Character Select Forcing). Although using it on Elma herself activates Elemental Awakening, one can get around this by using it on one of the Ghost Elmas. There's no way to free the Party Gauge until all Ghost Elmas are defeated (even if there are more than three), meaning the fight can get downright hellish if the AI isn't being very cooperative with its Blade Combos. They're also more hardy and dangerous than the Minirosas or Ardainian Musses. Finally, when you get to the fight with Elma herself, she's a doozy of an opponent; she constantly enrages just like Ardainian Kurodil, has massively damaging Arts, great evasion, and a very dangerous "Combat Limbo" Art that shackles the aggroed Driver and creates a damaging area of fire around her, which the AI happily ignores as they burn to a crisp. The only reprieve is that, if you manage to hit her, she's susceptible to Driver Combos because she's a human-sized opponent and doesn't have additional Break resistance from her size (on top of her already high Break resistance). "Elma Redux" also has the honor of being a difficult fight even on the easiest custom difficulty, so if you're cheeky and want to obtain her during a New Game main story playthrough, you need to be crafty about it.^note To stand a chance, the player must use a Dark Blade Combo to seal reinforcements and then defeat all three of the Ghost Elmas, ideally with Corvin; even at the easiest difficulty, Elma's Overdrive Art is a One-Hit KO and Party Gauge access is absolutely vital.
• Getting to 100 percent Community in Torna. You need to get both Monster Granny and The Nopon Halfsage. In order to get the former, you have to defeat 16 Unique Monsters. For the latter, you have to spend a total of 750,000(!) gold to buy the locations of four Golden Monsters and then defeat them. The highest-level monster is level 100, so you'll have to grind all the way up to the max level in order to do this. Clearing every single sidequest and the campaign will put you in the low 60's.
• For that matter, defeating said level 100 monster, Hurricane Anise, on Bringer of Chaos. While on the surface she isn't that much more threatening than the superbosses in the main game, the problem is that your team and setup options are much more severely limited in TTGC. Each Driver only has two accessory slots, some of the most powerful versions of accessories are unavailable, and most Aux Cores only go up to level III with a few stray level VI Aux Cores that are earned by completing Affinity Charts. Common loadouts from the main game (such as max agility/dodging and Driver Combo setups) are therefore much harder to pull off, making Hurricane Anise on BoC a Luck-Based Mission in some ways. On top of that, the boss is completely immune to Break and is very likely to undergo Elemental Awakening if hit with a Special, making Driver Combo specialists like Lora and Addam much less useful and forcing cheesy strategies such as spamming Mythra's Lightning Buster while backing her up with team support from Haze and Hugo. In fact, the battle is one reason why Haze is considered such a necessity and why she's preferable over Jin on higher difficulties despite his bigger story role and greater offensive prowess.