[@Iatos] [@olcharlieboi]

 I think its ok, after all, the humans are very religious, and getting holy / blessed items and water isnt that hard.

Unlimited regeneration would be kinda op, i agree, but make it something like, he can regenerate until he gets to fatigued to do so (it takes a toll on him), but even if he colapses on the ground, and people keep stabbing him, he wouldnt die, because you need a SPECIAL way to defeat them.

Resuming: you can incapacitate him by brute force. is very hard, and it takes a great deal of strenght, time and some effort, but its possible.  In order to kill it, you need a something else, like a ritual, or something.

This will make it so we can incapacitate him without hurting him permanently (by having to use holy and blessed items). Its common to see in movies / stories & such that they needed to incapacitate the demon, or trap them, and then perform a ritual to banish them.