[weakly from. from. possibly a heap on the floor at this point. breathing hard and having approximately a million too many feelings, but voice flat and businesslike, if hoarse]

It's a nonhuman entity that's unable to die in its natural state and possesses humans in order to do so out of boredom and exhaustion with immortality. From that, I'd assume that it's sufficiently bonded to Fire that he'll die if it does, otherwise there's no point. It's also a braindead sadistic idiot but that's immaterial.