lmao, the arm scene.
Although, the explanation that healing a healthy body causes necrosis seems really potentially serious. Saints/priests would be really OP then, with non-projectile magic that could just take a limb/decapitate, especially if they can do area heals/etc. If it was just self-inflicted damage from not being able to control a magic spell that'd be one thing, but the explanation was that it was the effect of the spell hitting an "improper target" vs just internal magic going haywire that'd only be capable of hurting the caster.