Agreed on all counts. I even got emotional when the evil Morty theme started at the end. The episode is full of Easter eggs and stuff that will most likely pick up in next episodes. I really like the Evil Morty arc, now I have to go compare this one with the other Evil Morty episode.
I bet there is full of things hidden in between the two, that's what makes the show so great. I have even started to watch "breakdown" videos on YT to catch the stuff I missed. I also watch every episode multiple times.
Part of me thinks that Rick believes Evil Morty is dead-- that he got him killed. It could be darker than that. Maybe Evil Morty finally stood up to Rick over something, and Rick-- while trying to subdue Evil Morty and bend him to his will-- underestimated him, saw things get out of control, and accidentally killed him (I don't buy that even Rick would deliberately kill his own family). This was his true, original Morty. He blames himself for what happened, and that's why he's so cynical, and so resistant to attaching himself to our new Morty.
Meanwhile, Evil Morty somehow survived the ordeal, and when he returned, part Cyborg, he discovered that Rick had
replaced him with another Morty. How did Rick do that? Unclear. How he did it could be extremely dark, and is very well the reason for the Council of Ricks came to be. Alternatively, although I can't figure out the logistics of it, I suspect that our Rick was the one who
founded the Council of Ricks.
Anyways, back to Rick replacing Morty. I have a hunch this was the first time Rick ever did this. Before, like most of us, he would have been horrified by this detached approach to the individuals between universes. After all, if you don't care about one-- if an individual cannot be special to you-- then you don't really care about any of them. Nobody is special, so nobody is worthy of being cared about. He's broken and nihilistic.
Perhaps this was what attracted him to Unity. If Unity were to take over the universe it would wash away all individuality. If that happens, then it's almost like Evil Morty (who he believes is dead) never existed; because if there is no individuality, then when any one organism belonging to that hive mind dies, it's like he didn't really die. You conquer death. At the heart of this Rick is grappling with the greatest challenge we all face: Death. His nonchalance about walking over corpses between universes-- including his own and his family's-- is a reflection of his inability to cope with death and loss.
The show literally has reinforced the idea over and over that we cannot trust any universe within this multiverse to have integrity. Our own Rick and Morty abandoned their original universe, after all. They don't even inhabit it. They buried the Rick and Morty that belong to it in their backyard. Furthermore, in the episode where Rick fakes out Nathan Fillion in the mind machine with a false origin story it is hinted that Rick did suffer a past trauma. Perhaps it wasn't his wife he blew up, but Evil Morty.
However it happened seeing himself replaced is what broke Evil Morty's belief in Rick. Now his life mission is to see all Ricks neutered of power, and enslaved by their own Mortys. He sees Rick as an oppressive, cankerous, uncaring force against his kind who isn't capable of anything, but that. So Rick must be brought to his knees. He must be torn down.
Of course, there's a potential problem with this theory about Evil Morty being the original Morty, and that's Campaign Manager Morty. He sought to assassinate Evil Morty once he discovered his origin story (the one we don't know, and are speculating about here). This was a Morty who wanted a Morty to be President, but didn't believe that possible. So why would he kill this Morty if he discovered his plans were to overthrow the oligarchy of Ricks? A possible explanation was his reaction to Evil Morty's debate speech. Campaign Morty wants harmony, and less division. He wants reform, not revolution. That's actually a satisfactory explanation.
On the other hand, maybe Evil Morty isn't a Morty at all, and what's what Campaign Manager Morty was trying to reveal to everyone. Maybe he's an android, not a cyborg: purely synthetic. It's possible Rick built him as a coping mechanism, and this is a cautionary tale about not playing God. The AI went rogue, and broke bad. It doesn't just want to enslave all Ricks. Maybe it wants to destroy all Ricks and Mortys.
An alternative explanation is that this Evil Morty is actually a double agent built by the Galactic Federation. He's actually working for them because the Council of Ricks is the only true force in the universe that can keep them in check. I don't really favor this because they've proven to be bumbling idiots so far. They couldn't even pull off what Evil Morty is doing themselves-- much less build a robot capable of it.