Aw, look. They have matching fatalisms.
Dean (about fighting Lucifer)
Cas (about fighting Lucifer)
Also, this episode is so cute that Cas assumes the best about his resurrection. We the audience may be feeling disturbed, but Cas's first instinct is faith in something higher:
(It won't be until Raphael suggests otherwise that Cas feels the first glimmer of the negative possibilities.)
Cas's fatalism isn't all about the failure of humans, I don't believe. As we'll see in s6, it's also the trauma of being murdered so easily by Raphael, after eons of loyalty and military service.
And this is tough on Dean too, because at a time when "invincible Cas" with and "unshakeable faith" might soothe Dean's newest vulnerability, Cas doesn't have much of his own faith to share. There's a lot of matching fatalism, as it were.
Even though he showed up to save them at the castle, Cas is angry and disillusioned right out of the gate.
Dean, Bobby, AND Cas are all feeling its effects. Cas is disillusioned with Heaven, with humans and their weakness; he's maybe afraid of his own weakness, Dean is spiraling because Sam sucks, and Bobby is newly disabled. What a mess!
But Dean and Bobby and Cas all manage to crack me up, because Bobby after telling Cas to shove his "I'm sorry" up his ass, is now saying this:
Hilarious, coming from the dude who was the first cranky old man in the whole damn scene.
CAS: Great all I'm saying is we NEED god to kick Lucifer's ass, so now gimme your fucking necklace
And just like that, symbolically another of John's "duties" is passing to Cas. This was a gift meant FOR John. It was trust passed from Bobby to Sam, then from Sam to Dean, and now the trust is passing from Dean to Cas.
Later, when Cas completely loses faith in God, his nihilism will spiral all the way down, to Cas throwing the amulet away, to Dean throwing the amulet away too.
And I don't have a clear idea of it, but there's something interesting I can't put to words... in Dean telling Cas not to lose the good-luck talisman. Something about how Heaven lost the Michael sword and about Cas hiding the Michael sword.
Idk, I just feel like this whole exchange of emblematic of Dean and Cas's dwindling hope and faith and their mutual disillusionment with the world.
They get really mad at each other and disillusioned with each other... and yet wind up supporting each other anyway.
And then Sam, still at the kids' table somehow, digging the hope out of the rubble. Dean sacrificed and sacrifices his own happiness in the name of familial duty, and Cas does the same. Sam definitely has moments of his own nihilism, but his hopefulness is definitely one of his more endearing qualities.
