i was just thinking their would be a rare chance that a monster would be possessed by a demon and look different than the original monster and drop the soul of the monster (as a material)
THEY APPEAR MORE OFTEN THAN THE OTHER RARE MONSTERS
example: wolver soul is a ingrediant for the wolver cap and coat
But... it isn't....
And if you do this, you force people to hunt these demonic creatures. And since they are rare, wolver coats would rise in price and its just a mechanic nobody would enjoy.