Just had a strange occurrence related to "Crawling Infestation":
I went to Phantom Forest and battled one of the infested knights, who managed to apply CI to Wulgraf. According to the status effect, I have 3 turns to kill the enemy before CI kills my guy. However, after just one turn, Wulgraf got killed. According to some other thread I found, CI seems to be useless for your own party, but what I had here paints it pretty OP for the enemy.
Edit: Probably found the reason for what happened. It might be that with the very last AP of his turn, Wulgraf walked into the insta-kill area surrounding the entrance to Phantom Forest, which then killed him and triggered the death-effect of CI. The area is a little bit larger than the fog-effect, so I didn't notice it until it happened again later.