Remember when Dean still didn’t fully trust Cas and was still against even working with the angels, but as soon as Cas was in trouble and his life was threatened, he stepped in to save him, no hesitation?
My favorite thing about this moment was that this was frigging Alastair, not just any random demon or monster, but the creature responsible for torturing and breaking Dean in Hell. Dean knew a crowbar wasn’t going to do jack or shit against him, but he stepped in anyway. He faced off against the king of all his nightmares, against all his trauma, because he wasn’t going to let it touch this angel for one more goddamn second.