Neutonic

If the only way you can avoid death from an aggressor is to somehow burn them to death (push them to lava), then I'd assume its okay because you are provoked to do so

If it is anything other then self-defense, you would need 2b at the least for torture.

It could also be if your character is aggravated enough such that he would not feel right doing anything except attacking the person. However, burning someone to death seems a little harsh, and people will probably complain if you attack them without a VA, even if it is within the rules. So I wouldn't do that.