How did Matt turn evil? What'd he do?

He sold out to guarantee Janice and Matty earned a spot in Erica's new world.
Too bad he never read er mind that she was lying the whole time, and would never allow a dirty mutie like Matt and Matty in her paradise. except as a slave.

=-=
FU Kring

It was shown in the alternate timelines in the original Heroes that Matt always had the capacity for evil.