Sam & Castiel parallels: a thread

Both tried to use dark, corrupted powers to save the world

And both of them chose to sacrifice themselves without hesitation to set it right.

Both of them are younger brothers to powerful, gung-ho older brothers and have a distant, borderline abusive father who cast them out for following their hearts.

Both of them were tricked into completing an ancient ritual that had apocalyptic consequences.

Sam tried and failed to raise Dean from Hell, which led him on the path to using his demonic abilities. Castiel tried and failed to raise Sam from Hell, which set him on path to use Purgatory to become Godstiel.

Both of them were forced to kill someone who trusted them while they were not in control of their bodies.

Both of them were forced to nearly beat Dean to death while being controlled but were both able to regain control before it was too late.

Both of them proved themselves as leaders and gained a small army of their own, only to lose everything and everyone who followed them. Now they both feel like they are failures and shouldn’t be trusted to be in charge of anyone.

Both of them have been willingly possessed by Lucifer

Cas was the only one who believed in Sam’s plan to become a vessel for Lucifer.
Sam: “go ahead, tell me it’s the worst plan you ever heard.”
Cas: “I’m happy to say that if that’s what you want to hear...but it’s not what I think.”

And later Sam was the only one who believed in Cas’s plan to use Lucifer as his vessel:
Sam: “His decision deserves to be respected.”

Both of them were able to overcome Lucifer to prevent him from killing someone they loved: Sam stopped Lucifer from killing Dean, Cas stopped Lucifer from killing Sam.

Both of them have been “exiled” by Dean on more than one occasion because he was convinced they are “too far gone”, but they have never given up on each other.

Both of them see themselves in Jack. Castiel sees an angel too attached to humanity, so he is cast out and hunted by his own kind and Sam sees a motherless child born with cursed blood but who chooses to use his strength to do good

I will add onto this as I collect more on my series rewatch