he must have some deadly disease and that's his way of coping with it cause there's just no way he actually enjoys being treated that way. i get it, he's a masochist but i don't think that's the only reason
yes and no a human can only take a certain degree of pain? Even if you're freaky and you're into pain there'll be a limit but that limit is not killing yourself
i hope both of those crazy mfs at the end die fighting or something