The Key to Evil

 (Japanese (Katakana): 発動！XXモード！！) is the eighteenth episode of Tenkai Knights. It first aired on January 05, 2014 on Teletoon in Canada.

Summary
Beni tricks the Knights to travel to Quarton into a trap. Meanwhile, Gen begins to get suspicions of Mr. White. The Knights must now fight copies of themselves if they wish to escape.

Plot
Beni meets with Guren and the other boys just as school gets out. Guren introduces her to the others and she tells him she wants to show him something. She takes them to the docks and reveals that she'd tricked them. The boys are temporarily rendered unconscious. When they wake up, they realize they'd been transported to Quarton.

Another Guardian, calling himself Eurus, appears before them and tells them that they are about to take a test. The Knights have to battle evil clones of themselves created by Guardian Eurus. Meanwhile on Earth, Gen begins to get suspicious of Mr. White.

The Knights manage to Titan Fusion and Bravenwolf and Tributon destroy all the clones. Beni is surprised that the boys won and realizes she shouldn't underestimate them. Later, Gen, as Dromus, and Eurus meet and talk about how to use the Tenkai Knights' Titan Fusion to find the Black Key. While Gen is suspicious of Eurus's motives, the Guardian claims to be helping Gen to keep balance because Boreas is helping the other Knights.

In the episode

 * Guardian Eurus appears before the Tenkai Knights for the first time.
 * It appears Guardian Eurus is the one who gave Gen and Beni their cores and is responsible for their being on Quarton, like the boys and Guardian Boreas, but that is not confirmed.
 * The Knights (Bravenwolf and Tributon) unlock and use Titan Fusion for the first time.
 * Titan fusion is first introduced in this episode.
 * The knights are given evil clones of themselves possibly created by Guardian Eurus.
 * Beni transports the Tenkai Knights to Quarton, This is unknown how she received this power possibly by Guaridan Eurus himself.
 * Guardian Boreas states in this episode that the new mode the knights have made this titan fusion is a threat to the balance of tenkai energy which means why the knights don't use titan fusion no more in other episodes.

Characters
Note: All characters are listed in order of their first appearances in the episode. The time they appear is the time from the Japanese dub.

Episode
Note: This section should only contain full episode uploads made by the right holders. We do not wish to endorse any unauthorized uploads of full episodes on this wiki, as it would violate FANDOM's Terms of Use and further laws against piracy.