Vilius Tenkai Dark Tempest

Vilius is the main antagonist of Tenkai Knights. He was originally part of the Knights, but he wanted to be the best, so he became corrupted with evil and turned on them. He then infused Corekai men with his corrupted energy, hence the name the Corrupted.

He is voiced by Crispin Freeman in English and Yōsuke Akimoto in Japanese.

History
Vilius was once a Tenkai Knight, but his lust for power and desire to be better than the others made his Tenkai Energy corrupt and he turned against his former comrades. From then, he leads the Corrupted army to obtain Tenkai Energy and find Dragon Cubes in order to awake the Tenkai Dragon.

Once the Dragon was awakened it went on a rampage. In the end the Knights Bravenwolf, Tributon, Valorn, and Lydendor stopped the dragon, but Vilius escaped. Many years later Vilius set out to collect the Dragon Cubes in order to revive the Dragon again, this time under his control.

In the series
In "Vilius Revealed", Vilius notes that the Tenkai Knights growing confidence after having gain another cube, he then decides to take action and make his presence felt. Despite his advantage, he retreated from the battle once the Corekai stepped in to defend the Knights.

In "Dragon's Key", Vilius sent his forces out under the command of Slyger and Granox to attack Commander Beag's forces, until Dromus was ready with his invention which would capture and contain the soon to be revived dragon.

In "Vilius Unleashed", following the awakening the Tenkai Dragon, and it's capture, Vilius and Bravenwolf face each other in a duel. During the battle, Bravenwolf reveals his human identity to Vilius before he's destroyed. In the aftermath, Vilius revives and now plans to conquer Earth after taking Quarton.

In "Checkmate", he reaches the santuary of the Guardians. Suspiciously, Guardian Eurus was not there though.

In "The Dark Unlock", he attacks Dromus to get the Black Dragon Key and used it to unlock the Dark Tenkai Dragon.

In "A New Knight", he commands the Tenkai Dragon to attack the Tenkai Knights, but ends up loosing it by them. He uses the energy from the Tenkai Dragon to become super large and powerful. However, the Tenkai Knights use Phoenix Mode on him, which caused him to be destroyed.

In "Vilius Returns", the Guardians were deciding to revive Vilius and punish him for his actions. As they were bringing him back, his spirit was controlling Zephyrus and used him to gain extra energy once he'd be back. He used the energy to overthrow the Guardians and have control of the portal. When the Knights were trying to attack him, he drained their energy to bring back the Tenkai Dragon, but ended to split into black and white Dragon Cubes by Dromus, and absorbed the black cubes, giving him a new look. Back at the portal, he commanded Granox to attack the Knights and sent Slyger to Earth.