There really isn’t a lot to say here as I think the gifs make the parallels pretty clear, but I just need to express how well done and heartbreakingly the events of the first episode of S9 are revisited in the last episode of S9. Especially the way the dialogue is shot between Sam and Dean. From the holding on to each other, right to the pat on the cheek for the final goodbye - it’s all there. Only with the roles reversed…
Why Those of Us Who Don't Trust Ezekiel Aren't Just Overthinking the Situation
Exhibit A. It Takes Three Tries for Ezekiel to Give Up His Name
3 is a bit of a magical number in storytelling. Do something once, and who is to say the audience will remember? Do it three times, and at the very least, no one can say you didn’t try to hint that it was important. Ezekiel is asked for his name three times–and only on the third acquiesces to giving one.
The angel who does not recognize him. Ezekiel’s response is that he will be “happy to make [his brother’s] reacquaintance” after that angel disarms.
Dean, post Ezekiel taking out that angel. Ezekiel’s response is to “never mind” who he is, directing the conversation to who Dean is and what he needs.
Dean again, but this time with the added incentive of a holy fire. Ezekiel answers this time, but only after hesitating, only after looking around at the fire and realizing he’s trapped, and only with a name. Even when Dean asks for proof that he’s good, he answers vaguely, running around the subject: he’s sure there are many angels that are hunting Dean and Cas (only implying he is not one of them), some angels believe in the mission and in him and Castiel. Only when speaking of his injury and of the actual goal here, getting to and healing Sam, does he truly use the word “I”–a common mark of a liar.
Exhibit B. Ezekiel is Never Interested in Sam’s Consent
While Ezekiel first presents the idea in a way that makes it seem like it’s a bad option he does not want to consider, he changes his tune the second it’s out there. He shows Dean what’s going on inside Sam’s head to push him towards making the call, he calls it the “best option in a bad situation” (a complete 180 in tone from the “no good options” line before), and seems perfectly willing to take a yes from Dean. It's Dean who has to remind him twice that his yes shouldn’t mean anything, that it’s Sam who has to make the call.
And the second time, Ezekiel makes it clear that while he also feels that Sam would not say yes, he does think Dean could make him say yes.
Exhibit C. Ezekiel Tricks Sam into Saying Yes
He doesn’t tell Sam what is happening. He doesn’t tell Sam of the consequences. He even twists Sam’s request for more information into a sort of consent by asking him if by that request he is saying “Yes”–which comes with the nasty side-effect of Sam being able to eject him if he ever finds out. (And how does Ezekiel deal with this side-effect? By wiping all of Sam’s memories so he won’t suspect a thing, so that Dean does not have to explain the situation.)
Granted, this bit of evidence requires a belief that it was Ezekiel, and not Dean, that was in Sam’s head at the end of the episode. While I understand that there’s some contention on that matter, I have no issue arguing on that assumption because to digress slightly, everything in the episode indicates that it is Ezekiel.
Ezekiel makes no motion towards Dean, allowing the audience to intuit that he was putting Dean back in Sam’s head.
What Dean says he said in the chapel, in the car at the end, is distinctly different from what Ezekiel!Dean says he said in the chapel. It’s a “You’re capable of anything” mentality versus a “it’s you and me, through anything” mentality.
The special effect is clearly one of shapeshifting (and basically the same one angels such as Lucifer and Gabriel have used before in similar tricks). It transforms Ezekiel!Dean into Ezekiel, versus Ezekiel appearing from behind or bursting in in a show of light.
Angels have been shown to be able to read minds and pull information out of a victim’s head (Lucifer, maliciously; Cas, non-maliciously). While the ability is ill-defined, it is perfectly within canon rules to have pulled a snippet from the chapel to fit his argument. Especially when the bit he pulled, as mentioned, differs from Dean’s account and really only serves his argument. Which, speaking of:
Exhibit D. Ezekiel and Hael’s Arguments Mirror Each Other Perfectly
That is to say, both focus on the combining of two into one, in what they preach as a mutual partnership but only leaves one person truly in power.
I’d be lost without you, Castiel. It’s the least I could ask of you […] We’re going to become more than just friends, Castiel. We’re going to become one. […] You were right, Castiel. With us, together, I think I could learn to like it here.
I can fix this, but not if you shove me out. […] I made you a promise, in that church, you and me, come whatever […] But you got to let me in, you got to let me help. There ain’t no me if there ain’t no you.