Sigma Virus

Sigma Virus
The Sigma Virus is a virus that turns Reploids into Mavericks.

In Mega Man X5, it appears as a enemy that looks like a purple floating Sigma Head. If X gets hit with it several times, he will get a condition that damages him for a while. If Zero gets it, he actually becomes stronger (mainly because he was the one who carried the virus before Sigma got it).

Zero Virus
Zero Virus is a enemy from the final stages of Mega Man X5, a purple virus that looks like Zero.