Etymology: He's very smart and evil (10/10 on the Evil Scale), so...
The Evil Brainiac was the most prominent villain in Valliyv. He, along with his helper Threats, caused the Great Explosion, which destroyed the World of Valliyv, and himself. He was not a demon, despite popular belief, but was instead a proficient necromancer and managed to, with Threats' help, maintain his life over many millenia. His long life was also related to the loss of his body during his first, failed mission to destroy Valliyv. Now, his brain was encased in a large jar and kept alive by a Moonriver solution. His new, robotic body improved with technological advancement, and he quickly regained many of his former capabilities (although he would never cast spells again).