I'm hitting a problem where I should be stealing life (from imps and other low-level monsters) but it's still deducting HP. At first the fang does steal life, but then it stops working as intended after navigating the tower and fighting on different levels.

I'll post details if I can figure out exactly when it stops lifestealing, but this bug is frustrating because it makes the last floors much more difficult than they should be. :/