@ OP, if you keep hearing "I heal myself while walking on lava"
If you're a developers, what's your first reaction and of course your next course of action?
There's a part of the game that's ONLY ACCESSIBLE if you heal yourself while walking on lava. The imp's all "There's three paths: one through immaculates, which there's a lot of but are weak, one through super buffed demons that can only be hurt through tenebrium, and one that is full of lava, so you'll need to be immune to go that way." So, having been maxing my fire resistance, I went that way. Gaining lava immunity is clearly part of the original design.