Can we talk about the fact that Dean drank an entire 26er of hard liquor and was not only still cogent, but went out and drank more alcohol at the bar afterwards? It’s already been established that Dean has an immense tolerance for alcohol, but even though he might normally have been capable of drinking that amount and not dying/getting really sick/just passing out, he should not have been as cogent and functional as he was at the end of the evening as he was after all that alcohol.
Dean’s alcohol consumption in this episode is actually at an absurd level and I don’t think it’s just to highlight his use of/need for alcohol as a coping mechanism. I think the immense amount of alcohol he drank with little effect is to highlight that the Mark is changing him, in unanticipated ways. He’s becoming less human in many ways, he’s more brutal, more animalistic, now he’s not affected by alcohol the way a human is? While demons have been shown to drink, they’ve never been shown to be affected by alcohol (to my memory). Could we be looking at the first hints that the transformation to demon!Dean is already underway?