User blog comment:McGillicuddy/Luzifer in Season 10 ?/@comment-103.36.47.150-20150515033059

Well, Metatron did say that "the river ends at the source", this made me think that since Lucifer was the one who gave Cain the Mark and since Rowena said that it's "just a curse albeit the very first curse", they can easily be removed by killing the curser who in this case is Lucifer (unless it isn't?) and the promo of e23 kind of implies that maybe Dean is given a task which is "sizable" according to Death and maybe this task is to unlock the cage and, since he is given Death's Scythe which can kill anything, perhaps entrusted to kill Lucifer forever UNLESS the curse wasn't set by Lucifer which would maybe be a completely different plot or it could be someone deadly OR since "Death" is concurrent to "murder", maybe Lucifer asked Death to curse Cain in the beginning which is why he was imprisoned underground by God and the promo implies that Death asks Dean to kill Death with his Scythe AND become the new Death in return (for whatever reason).