User blog comment:EmpyreanSmoke/Supernatural Q&A (Closed)/@comment-27014555-20151114222607/@comment-3045936-20151115043703

Than how could Dean kill Cain. Death said that whomever holds the first curse, (Nothing) can kill you. Also if the First Blade is the exception, still goes to say. Than, what happened to Cain's part of the Mark. As if the mark was split than, even if Dean's was broken than how could the darkness be released? The entirety of the First Curse needs to broken I would guess. These are what the show has shown me. Also Em, not answering the question per say. More as asking myself and giving the information I found.