The Evil Energy as it is called, is a mysterious and dangerous energy source of alien origin and it plays a major antagonistic role in Megaman 8. Usually, it looks like a swirling purple flame in the shape of a skull.
According to Duo, this type of energy absorbs evil within a person's mind and then multiplies to infect others--mainly robots and other machines, in the course of the game. Due to this method of replication, the original source can only be harnessed by beings of pure malice. This dangerous type of energy is capable of infecting the entire cosmos one planet at a time.
The benevolent robot Duo hunts down this 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. He even once fought an evil-looking robot in space that was infected and consumed by the Evil Energy. Duo finally succeeded in destroying the original Evil Energy with the help of the heroic Megaman who stopped Doctor Wily 's plan of using the Evil Energy to power his loyal Robot Masters in his never-ending quest of world domination.
- It is often speculated that this energy itself was the basis of the Maverick Virus, but it's unknown if there is a connection between them and the Roboenza.
- According to the content that was in the Rockman Zero Collection official site, Dr. Light made X with a perfect virus counter-measure because of an unknown computer virus of alien origin that caused robots to become violent and riotous. The virus mentioned is believed by some to be the Evil Energy. (Translation in The Mega Man Network).