WTF he's death!! Sewers SPOILER!

[BendyBread]

One one hand I think the shadow did it, seeing as its totally taken over that room and FR are trying to show us the damage it can do.
On the other hand, I think mr.tall did it, seeing as the body is cut cleanly in half. Combine that with the fact that mr.tall can kill you in like 1 hit, where as mr.face takes 3-ish hits/