I think you hit it on the nose with AU Castiel. I'd been making notes for an alternate theory after they talked about a 'surprising' twist at the end (Michael really wasn't that big a surprise, sorry) and Naomi saying that Castiel came out with a 'crack in his chassis' just couldn't have been limited to one universe.
I'm mostly sad they didn't get a chance to highlight what the difference between AU and RU were.

Oh wow... I just finished watching season 13. I’d actually read this story before- I wasn’t sure if I’d ever watch season 13 but then reading fanfics tagged to those episodes finally convinced me to watch it.

That being said. Wow. Just... whew. I didn’t realize some of the things you’d pointed out about apocalypse world castiel.

Can we get a sequel please? this is awesome and I wanna see what happens next?

This was great. Incredibly painful but beautiful. I love your take on that world’s Castiel. So damn angsty and so perfect. Thank you for sharing this!

I'm not crying, you're crying...this was so beautiful!

Yes, perfect, amazing. This broke my heart and taped it back together. I love it

This is so beautiful and well-written. Thank you for looking past the obvious and redeeming Apocalypse!Castiel.

Soooo yeah...I’m crying into my morning coffee now. I never ever thought of this, of the effect that seeing that version of Castiel would have on Cas. I mean this whole thing is just so damn gorgeous though. And I love Sam comforting Cas because we don’t see a lot of Cas and Sam and they are friends too and this is definitely something Sam can relate to. Ugh I just have a lot of feelings about this. Thank you SO much for writing it. Beautiful job.

OH AND ALSO your title is perfection, more applause for you. :D

I. Am. BROKEN.
That was BEAUTIFUL. Beautiful.
When Cas said, "He did! And they destroyed him!" I just about vanished from this plane of existence. Pretty sure I stopped breathing, anyway. Was definitely freaking out. My next though? CURSE THIS SHOW FOR ALWAYS MAKING US FILL IN THE SUBTEXT FOR THE BEST PARTS OF THE STORY. ((But also bless this show for having so much good potential material...)) Seriously, though. It drives me crazy when the writers drop stuff like Alt!Cas into the show with nooooo follow-up or in-depth character explanation, and there's such GOOD STUFF lurking RIGHT beneath the surface, but the fandom has to dredge that up ourselves because it's rarely ever written into the actual show. And that begs the question - are they doing it this way on purpose, or are they just clueless? ... *sigh* ... In any case, I am grateful for authors like you who give these wonderful characters the appreciation and depth they deserve.
Some notes on the story: When Sam went back into the Bunker, I really thought he was gonna go get Dean, but this was better. Cas didn't need to be hashing all this out right now, he just needed a friend. Also, why the heck didn't I notice that Cas wasn't acknowledged along with Sam & Dean? Oh my soul this show does not appreciate Castiel enough (although your reasoning, about him being an angel and therefore an outsider to the humans they saved, makes perfect sense). Thank you for bringing that lil factoid to my attention. This was brilliantly well done, and I applaud you.
Thank you for writing!
~ Clara Brighet

This was damn awesome. And it inspired me to write something too. I hope it lives up to your example!

I'm thinking you need a bit of a stronger warning in your A/N than "Basically it's just an angst-fest." It took me far longer to read than it should've because I had to keep stopping so I could have a good cry. Thankfully no one's around so I don't have to try to explain why I'm crying over my Surface.

29P, I think this is the most beautiful, heartbreaking, amazing thing you've ever written. It addresses a lot of the issues of not only that episode (honestly, I was ready to take a gun and start shooting humans, starting with Bobby, when the sonofabitch didn't acknowledge Castiel at all, just Dean and Sam) but also the whole series with regards to how they treat and ignore Castiel and what they've done to him. It's criminal. I'm glad you included Sam in this as he's more sensitive than Dean, and I'm glad you write both Winchesters better than the series as well. Because I tell you, I included canon Dean and Sam in the humans to shoot after Bobby because *they* never said word one in support of their angel either and it left me seeing red. There is nothing about this I didn't love and very little about it that didn't make me cry - between Castiel trying to explain to Sam's floundering attempts to offer comfort to finally getting it, between Castiel's oblique admission to how he feels to Sam's stalwart admission that Cas *does* matter, very much, and that he *is* loved.

The end in particular offers a promise and hope and maybe even a little comfort: "And (Sam) knows what it's like to have someone waiting there to catch him. So he'll be waiting as well, to catch their angel whenever he falls."

Thank you so much for sharing your wonderful talent, for sharing *this* moving piece for everyone else to enjoy, for making SPN better through writers like you who fix what they in canon break. Thank you!

Wonderful brother moment between Cas and Sam! That scene should have been in the show. Heartbreaking. Tense.

a Lot of thoughts i had as well watching that episode. they treated Cas as if he wasn,t part of the team and even Dean and Sam didn,t say a word to change that. i found that to be so sad.

OW! OW OW OW OW OW!