I'm forever a Dean defender and that's why I stand by the concept that Game of God hits the hardest in terms of phycological consequences of the space and time displacement of Dean Winchester.
When the lines between Dean in hell (aka Alistair), Endverse Dean and Dean actually begin to blurry in Dean's mind was after the daycare fight— and what happened to Grant.
A bit later (a few days after that tragedy I think) he went to explore the Sisters of Mercy's church with Cas and completely forgot that he wasn't there before that night in Kansas City. He goes "if we had known the sisters where here"— but he could not known, he didn't appear in the Endverse until three days before the Kansas City attempt to kill Lucifer.
It keeps building and by the time we reach Game of God, the circumstances make everything worse than it could possibly be. His displaced guilt and his inability to forgive himself for things beyond his possibilities (what happened in hell, what the other Dean did) sets him on a very familiar cycle of self-destruction.
What Dean learned in hell was to broke himself more than anything else. Alistair destroyed him from within and left the enemy inside him, so that Dean would continue to torture himself even after he was out of hell.
What I mean it's that Dean has to deal with two totally different versions of himself that he could not prevent from happening. He is paying for sins old (time) and sins he didn't even commit (space).
Even if he's been months on the Endverse, you're asking Dean to carry the burden of three different lives. It's insane. He tries so hard not to break and the only other person who knows what he's going through is Cas.
Give that poor man a rest 😩😩
