Long ago, in the cult of ancient echidnas, one of the high members, Dimitri, he created a suit for emitting chaos energy, unfortunately his helmet revealed his red quills, so his secret identity was soon discovered, but he continued to rampage, until Sonic intervened and defeated him, resolved from the fight, emerges Super Sonic, with victory intact he flew off, but Dimitri survived, and was rebuilt into a mechanical sphere with steel tentacles and infared eyes, since then Knuckles the Echidna has taken on the role of Enerjak through a trance.
Mario Forever 4
With the use a new time machine, Chrome hires Enerjak to join his cause.
Mario Forever 5
Enerjak is hired to follow Mario while he infiltrates Immortus' HQ.
Mario Forever 6
With Armageddon drawing closer, Enerjak reveals his identity and imprisons Immortus in his body, then leaves to follow Chrome into the rift.
And continues in the Mario Forever (Series)
Enerjak made his debut in Sonic the Hedgehog #35