...Millennia ago, the peaceful cube–like planet Quarton, populated by shape–shifting living bricks, was ravaged by a war between the Corekai and the Corrupted, led by the ruthless warlord Vilius who desired to obtain all Tenkai Energy for his own purposes. However, the only ones who were strong enough to defeat him were the Tenkai Knights: Bravenwolf, Tributon, Valorn, and Lydendor.(and also Dromus and Venetta). Facing defeat, Vilius unleashed the mighty Tenkai Dragon, the beast was defeated by the four Knights and its fragments were scattered. These heroes were never seen again, but the Corrupted have returned more powerful than ever. A group of four (later joined by 2 others) kids have chosen to become the new Tenkai Knights, in order to save the both worlds from Vilius' tyranny.
A second season was announced, but it was cancelled before production.
Tenkai Knights contains examples of:
- Aborted Arc: The Knights' Titan Fusion is used for a few episodes and then quickly forgotten, probably because they did not win new powers by fusing; instead merely got one robot who could use two weapons.
- The Ace: Chooki Mason is ridiculously good at everything he does (mainly sports), and everyone knows it. Many kids look up to him (while some envy him). Despite all this Chooki's a pretty modest guy. He is even the most skilled knight in the battle, and the group's second-in command.
- Age Lift: In the Japanese version, Guren Nash is 11 years old. In the English dub, he is aged up to 13.
- All There in the Manual: As is typical with shows like these, there is often information that can be found on the official website
that can be a toss-up on whether it will be revealed in the show proper or remain "in the manual". - All Your Base Are Belong to Us: Toxsa says this almost word for word in episode 22.
- All Your Powers Combined: How the Knights defeated Vilius in the season finale.
- Alternative Foreign Theme Song: The Japanese version has a different opening and ending theme.
- Anime Hair: Ceylan has blue hair, while Guren's hair is red in the front and black in the back.
- Another Dimension: Quartron, a cube shaped world that is far from Earth. The kids travel there by way of a special portal located in the basement of an antique game and hobby store.
- Apologetic Attacker: Combined with Fighting from the Inside, the Mind Controlled Guardian Notis continually tells the Knights he has no wish to fight them but can't resist Vilius's control.
- Animesque: Like Spider Riders and Monsuno, this show is done by a Japanese-western company co-production team that can easily be considered both an anime and a western cartoon.
- Back from the Dead: Vilius has the power to resurrect his henchmen as many times as he wants.
- The Bad Guy Wins: Episode 23 ends with Vilius getting away with the black key while Guren and the others are forced to watch helplessly.
- Balance Between Good and Evil: Keeping Tenkai Energy balanced is the MO of the Guardians of Quarton. This is why Boreas recruited Guren and the other kids in the first place.
- Big Bad: Vilius is the leader of the Corrupted army who is the one leads the assaults on the Corekai army and the knights.
- Big Damn Heroes: Many, one moment from episode 25 stands out.Granox: (about to finish off the Knights, when an explosion interrupts) "What happened!?"
Beag: "BEEEEAG WAH HAPPEN!" - Big "WHAT?!": When Guren finds out his father is aware that he is Bravenwolf, he boasts one of these.
- Call to Adventure: Provided by Mr. White.
- The Call Knows Where You Live: Once a core has chosen someone, it will refuse anyone else and stick to that one person like glue.
- The Chosen Ones: Guren, Ceylan, Toxsa, Chooki, and Beni are this by the core.
- Cannot Tell a Joke: Commander Beag, he's not very good at trash-talking either.
- Chekhov's Gunman: Both Toxsa and Chooki make brief cameos in episodes 1 and 2 before they are officially introduced in episode 3.
- Clingy MacGuffin: The Tenkai Knight Cores' seem to work this way, since every time Ceylan tried to give the Tributon Core to Mr. White it always found it's way back into his pocket.
- Color-Coded Characters: The colors of the kids civilian cloths match their Tenkai Knight armor. Guren (and Bravenwolf) is red, Ceylan (and Tributon) is blue, Chooki (and Lydendor) is yellow, Toxsa (and Valorn) is green, and Beni (and Venetta) is pink.
- The Corruption: Vilius's army is referred to as "The Corrupted", though the exact connotations have yet to be explored.
- Crystal Dragon Jesus: Played with the Tenkai Dragon, the dragon is apparently not worshipped, but it is a God-like beast formed out of magic techno-organic blocks.
- Deus ex Machina: The introduction of the Tenkai Wolf feels like this.
- Dreaming of Things to Come: Both Guren and Ceylan have had visions of fighting on Quarton in the form of dreams. This would happen to all boys from time to time.
- Easily Forgiven: As of episode 26 Gen, Eurus and to a degree, Beni.
- Engineered Heroics: An interesting case, Beni setup her first meeting with Guren with the ruse that he was saving her from a nasty fall in order to get close to him.
- Epic Flail: Lydendor carries a weapon that's a cross between a flail and a whip.
- Evil Plan: Vilius seeks the Tenkai Dragon so he can Take Over the World. It's a step to taking over everything.
- Expy: Gen Kurai strongly resembles Sasuke with the hairstyle, clothing, personality, emo appearance (this is lampshaded by Toxsa himself), and even share the same voice actor, Yuri Lowenthal. He also works with Vilius under the guise of Tenkai Knight Dromus; and serves as The Rival and Evil Knockoff to Guren.
- Fallen Hero: According to the official website, Vilius was once part of the Tenkai Knights himself, a highly respected part of the Corekai, until his greed got the better of him and he was cast out. It was then that he decided to overthrow the Corekai and eventually rule the entire universe.
- Galactic Conqueror: Vilius' ultimate goal is to take over both worlds, so he can be acknowledged as a god, and begin his universal conquest.
- Henshin Hero: The characters become the Tenkai Knights when they cross over to Quarton.
- Heroes Prefer Swords: Bravenwolf wields a sword in battle.
- Honey Trap: Beni meets with Guren to gain his trust in order to learn why Gen is so fixated on (and frightened of) him.
- Hot-Blooded: Both Guren and Ceylan have elements of this. Guren is more willing to jump into action, but Ceylan is more easily riled up. Of course, seeing that Guren's voice actor is known for these characters, it wouldn't be a surprise.
- How Do I Shot Web?: Guren and Ceylan's first trip to Quarton as Bravenwolf and Tributon. Most notable when they're falling from a great height with no way to slow their descent, that is, until their matter of fact A.I. helper plainly states that they have Tenkai Boosters, almost to late in fact.
- Hypocrite: Guardian Eurus appears to be shaping into one of these.
- Ice-Cream Koan: Mr. White is full of these and is more than happy to evade the boy's questions by using them.
- Incendiary Exponent: The Tenkai Proto Jet becomes wreathed in flames that form a Phoenix in battle.
- It Seemed Like a Good Idea at the Time: Toxsa forcing the enemy's mind reading device to take information from his mind instead of the Valorn A.I. was a clever way to prevent Granox from learning where the Dragon Cubes were being held. In hindsight his actions led to Vilius learning about earth.
- Kid Hero: The five main characters are no older than 12-13 years old.
- Mind Control: After capturing the Guardians Vilius uses corrupted Tenkai Energy to forcefully subvert their personalities and change their allegiance.
- Merchandise-Driven: The series is driven by the Spin Master's LEGO-esque Ionix toyline of building toys with a unique bricks that features shifting parts. These unique parts range from transforming bricks that forms a posable endoskeleton for the figurines to bricks that turns into weapons.
- New Transfer Student: Guren. When Ceylan throws a paper airplane at him when he's introducing himself, he doesn't fail to remark the cliched-ness of the act because he's new.
- Nice Guy: Guren. Despite his disagreements with his father's moving schedule, he's quick to befriend the Class Clown who paper-airplaned him while he was introducing himself to his class.
- No Sense of Personal Space: Gen once got Ceylan riled up by insulting him, while talking he kept grabbing Ceylan's arm for some weird reason. Ceylan for his part was to offended by Gen's insults to notice.
- Oh, Crap!: The boys first response when the learn that Slyger and Granox are not only still alive after what happened during their last battle, now they both have access to Titan Modes.
- Out-of-Character Moment: With Vilius in control of the evil Tenkai Dragon. Beni starts venting on Gen for losing the black key, adding that she never should have allowed him to handle the situation. Instead of snapping back Gen smiles gently, agreeing that they might have better luck going their separate ways and promptly rushes off to help the Knights.
- Powered Armor: Played with. It is noted by the Tenkai Knights' A.I. that the kids are not in Powered Armor, but rather have become the robots themselves. Though they are seen wearing color-coded plug suit-like uniforms via mental images for our benefit.
- Precision-Guided Boomerang: When Lydendor transforms to Titan Mode he acquires a boomerang-like weapon that comes back to him after he throws it.
- Psychological Torment Zone: The Valley of Secrets acts something like this and confuses all who enter.
- The Quiet One: Gen Kurai doesn't like to socialize with other people. This is because he is working with Vilius and prefers to work alone in secret.
- Red Is Heroic: Bravenwolf and Guren Nash.
- Red Oni, Blue Oni: Inverted with both pairs of boys. The ones associated with cold colors have red oni traits while those with warm colors have blue oni traits. To wit:
- Guren (red-colored) is calm and polite, while his best friend Ceylan (blue-colored) is a jovial dude who loves cracking jokes.
- Chooki (yellow-colored) is a born strategist who approaches everything with a cool mind, and Toxsa (green-colored) is a bratty and sometimes dumb loudmouth.
- The Stoic: Gen, then again, considering Yuri Lowenthal is known for these characters (when it comes to emo).
- Seemingly Profound Fool: The Corekai all marvel at the Tenkai Knights. With Beag saying they are a bunch of tactical geniuses. Unfortunately, the boys don't even understand what's going on half the time and usually win a battle by the skin of their teeth.
- Shout-Out: Villius' proclamation that "Words don't win battles" seems like a direct counterpoint to 'Words Win Wars'.
- So Last Season: When Slyger and Granox finally return in episode 16 after a three episode absence they both display the ability to transform into Titan Mode to challenge the heroes.
- Spirit Advisor: Boreas, the Guardian of the portal to Quarton in Mr. White's shop often appears before the boys as a hologram to explain the history of Quarton and advise.
- The Starscream: Gen's not even being subtle around Vilius about the fact that he's just using him to get the Tenkai Dragon's power for himself.
- Super Mode: Tenkai Titan Mode.
- Golden Super Mode: The Tenkai Dragon separates back into the 5 dragon cubes that merge with Bravenwolf, Tributon, Valorn, Lydendor and Dromus, allowing them to enter Phoenix Mode to defeat Vilius.
- As of episode 27 Vilius takes the Dragon Cubes back, taking away Phoenix Mode, as well as uses a staff that suppresses Titan Mode, but absorbing the good dragon's Tenkai energy grants each knight new powers to match Titan Mode. They don't change size, though their armor is altered.
- Temple of Doom: The Temple that lies within the Valley of Secrets, with a Death Course that's equipped with a fully functional Laser Hallway, boulders that squash intruders, and of course Pit Traps.
- Transforming Mecha: The premise of the show is based on an entire other world filled with Transforming Bricks powered by the mysterious Tenkai Energy.
- Well-Intentioned Extremist: Guardian Eurus, if his claims are to be believed.
- Workaholic: Implied with Guren's father. Instead of seemingly being distant from his son, he acts like a pretty cool dad onscreen and hasn't been seen actually working yet, but it's said that he spent the last two years working instead of paying any attention to his son and has had moved do to work three times during that period.
- Year X: Averted actually. The year is clearly defined as 2034. Cars with auto-pilot and navigation seem to be the norm and the kids each have bracelet-like items that allow internet connection, but nothing else seems to be too futuristic.
- You Can't Fight Fate: Ceylan at first decides that getting killed in order to protect the universe is not for him and tries to return the Tributon core to Mr. White, but the core is rather clingy and keeps ending up back in his pocket.
