Evil Energy (悪のエネルギー Aku no Enerugī?) is a mysterious sentient energy source of alien origin that appeared in Mega Man 8. Usually, it looks like a swirling purple flame in the shape of a skull. According to Duo, this alien energy absorbs evil within a person's mind and then multiplies to infect others—mainly robots, in the case of the game. Due to this method of replication, the original source can only be harnessed by beings of pure evil. Duo hunts down this Evil Energy to stop it from infecting the whole universe and possesses the ability to heal its victims if their minds are not completely consumed by evil.