i want to reblog and add to this post, but i cant bc the formatting gets funky. so separate post! little bit of endverse meta i guess. 

from the post:

why in 5x04 did past!Dean say to future!Dean "You mean you're gonna feed your friends into a meat grinder? Cas too?" Three episodes earlier Dean told Zachariah "I learned that from my friend Cas" so at this point he already considered Cas to be his friend. So why was he not grouped with the others when past!Dean said that? Why did past!Dean choose to separate those two for future!Dean? Is it because he knew that to future!Dean there was a difference between sacrificing his friends and sacrificing Cas? Did past!Dean pick up on the significance of their relationship during the days he spent in that timeline? Did he want future!Dean to know that he knew? Could he just read himself well enough to know that Cas was more than a friend to future!Dean? Did past!Dean already know that his feelings for his Cas were different than his feelings for his friends and knew that future!Dean felt the same?

this is how ive always read that line--that even by that point past!dean viewed cas as different from straight up FRIEND. and then observing how his future self and cas operated and relied on each other, and how cas basically served as 2IC for dean at the camp.

(which imo is HUGE ok. like endverse!dean explicitly tells past!dean that he doesn't trust him, i.e. that he doesn't trust himself, but he does trust CAS: he wants cas's feedback on his plans; he wants cas to help lead the plan. and i cant remember the question past!dean asks but in response chuck sends him to cas. bc like OBVIOUSLY that is where future!dean apparently hangs out a lot. cas is the person future!dean goes to with questions. it’s not weird or surprising at all to chuck that dean would be looking for cas.)

WHAT I AM SAYING IS, there is a deep amount of trust between endverse!dean and cas, and (at the very least) a deep deep bond of brothers-in-arms, i-have-your-back-and-you-have-mine, that goes above and beyond any other relationship dean has with anyone, past or present (present being endverse in 2014). sam is the only possible exception to this (and past!dean at that moment doesn't feel like he has that with sam, and endverse!dean obviously has not had sam around to serve that function for a while) but sam is also dean’s brother, family, the person dean has built in as the centre of his universe. having someone else who can even come close to matching that role is hella serious and important and even maybe shocking. 

all of which past!dean witnesses and understands. and can see how their relationship differs from his current relationship with cas. it's this window into a view of POTENTIAL of what cas could be to dean and for dean. and i think that resonates strongly (and maybe even a little uncomfortably) with past!dean because he can relate. the ground work to that relationship has already been laid down. cas is already a person he's coming to rely on to help him and sam and bobby out when they need it. and with sam currently out of the picture in that episode and the one before it, cas (and not bobby) is the person dean goes to and calls and spends time with. 

so i think past!dean absolutely knew that sacrificing cas was on a whole 'nother level and whole different emotional ballgame for him/his future self than sacrificing anyone else in the camp. sacrificing cas would be more akin to sacrificing sam and we all know how much NO NEVER that hits in dean. 

(and of course i headcanon that cas was in on this plan. that the plan actually was that they were both going to die, dean in a final face-off with lucifer (and sam) and cas in a supporting role letting dean pick the hill they were going to die on. because the alternative that cas walked into that situation blind just does not make sense to me. for starters, cas is weirdly chill about cooperating what he knows (and points out to be) a bad plan. an unworkable plan. cas also knows they’re using a gun that is repudiated to kill demons but not angels. only an angel blade can kill an angel. why, if the intention really was to try to take lucifer out, would they not at least bring an angel blade for back-up? if cas even believes that lucifer can truly be killed. (like, dude, this is ENDVERSE!CAS, the happy hysterical nihilist. cas has always been a pragmatic realistic, for good or for ill, and i can’t see anyone thinking that somehow endverse!cas got any more optimistic or idealistic during the five years of fighting the apocalypse.) i just cannot believe cas would legit buy that they could actually kill lucifer with the colt.

also there’s the cut scene in the script where cas tells past!dean that when dean says it’s time to go, i.e. when dean decides that they’re done living in and fighting this unwinnable war, cas is going to follow him. because that’s just how he rolls. which to me points to the original intention being that cas and dean had this joint suicide pact for a while and set up this plan to enact that out, and past!dean just isn’t privy to that information.)