Talk:Attack Types/@comment-27325982-20151201070207

San’s attacks do not poison you. The purple health acts as a health buffer, preventing you from dying straight away when you hit 0hp, leaving you at 1hp and giving you a chance to recover before the next round. This is similar to the “white health” mechanic in Street fighter except you cannot heal from it. (Didn't anyone get the impression that it was saving their lives rather than damaging them?)

(As others have pointed out elsewhere)  KR is most likely referring to his ability to ignore invincibility frames, KR being an antithesis to the “Mercy Invincibility”, the official term for invincibility frames. Hence the removal of the mechanic in Sans' fight was a genius move by Toby.