He is a former Highest born as part of the extinct zero-class who derive their power from the pain and suffering of others. Initially starting his life as a carefree, social and kind soul, Exeller's rage, grief and revelations of his past caused him to spiral into insanity and choose his destiny as a cold-blooded murderer, leading to his eventual death and subsequent resurrection before possessing the body of Sonic the Hedgehog in order to fulfill a prophecy by using the Master Emerald