You were supposed to save them but... instead you screwed them over and let them fall to the darkness. You were a coward and you felt horrible about it. Your friends...were now witches and were commanding legions of demons just to hunt you down and conquer the city. Not to mention that your decision to go to "that place" and the one to fix things only made things much worse. Even worse. It was your own handywork. You were manipulated into shooting your friends with bullets that were supposed to remove corruption. Instead your friends's eyes became dull and were engulfed in blue flames before revealing themselves as witches. The bullets were a lie. They killed them instead of killing the evil within them.
Elena, Sapphire, Talia and Constance were no longer your friends...but your worst nightmare. So you had to run with this mistake on your conscience. They were gone. Only malice remained. And they wanted to make you pay.