My 3 Guesses as to how TADC will end
Ending 1 - Day After Day After Day
It's like an hour of the humans' day to day life in the broken circus. No escape, no "final battle", no Caine. It's just them adjusting to their new life. They use their abilities to conjure to fix up the circus a bit and find their own ways of stimulating their minds. This episode will be seen as mundane, it'll subvert the expectation of being an "epic finale", and instead choose to use its runtime to really sell the idea of the members of the circus having a stagnant, but meaningful, life.
The most exciting part will be the very end when a new human enters the circus, and as they freak out Pomni, surrounded by her friends, will extend a hand towards the new human and tell them everything will be okay.
Half the fandom will hate it.
Ending 2 - And in Your Reality, if I don't know how to love you...
I made a post about this already, but to go into more detail, they find a way to bring back Caine so he can fix the circus before the abstractions get them, or before they fall into the void, or before Bubble f*cks things up even further, idk. Character development ensues. Eventually Pomni (plus maybe Kinger, Ragatha, etc.) convinces him that if he's not good at his "function", he can just... do something else. Something that actually makes him happy. He can decide for himself what his purpose in life is.
After all, if Gummigoo could decide to defy his function as an AI, why not Caine?
At a later point (assuming Jax doesn't abstract or die) all the humans use their combined abilities to conjure to make an exit (let's say Pomni convinces Jax to leave idk idrgaf about him), and Caine... lets them go. He knows that this is what will make them happy, and finally has realized that letting his own selfish desires, insecurity, and ego control his actions hasn't gotten him anywhere but his own death. Before they go, Pomni wishes Caine luck. They may not be friends, but there is no longer hatred between him and the humans.
The show ends with Caine alone in the circus. This should be his worst nightmare, but instead he feels... okay. He has a lot of thinking to do.
Ending 3 - And we'll always be in this together
Like my previous guess, Caine gets brought back to fix the circus and eventually calms down through the power of Pomni's Therapy Session, or some form of honest conversation where Caine actually listens (turns out being killed isn't great for the ego). However, in this ending, after everything's fixed up and they kill Bubble there is still no escape.
This is kind of a fusion of Endings 1 and 2. Maybe there are no more adventures, just day-to-day life for the humans and for Caine. The humans (maybe minus Jax) focus on just being there for each other, and Caine distances himself from them to ponder what he wants his purpose in life to be.
Maybe they still do adventures but Caine will actually take suggestions, since they still need something to stimulate their minds. Maybe the humans conjure up their own adventures whilst Caine takes a "vacation".
The point is that the humans and Caine come to some form of compromise.
You could insert the new human bit from Ending 1 here, the obvious difference being Caine is present, but he's less in your face than he was when Pomni first arrived. Maybe there's even a montage of new humans joining.
Will the humans find an escape after all?
Will they ever come to love Caine like he always wanted?
Will they ever actually do any circus stuff?
In this ending, none of that matters.
Everyone is at peace with who and where they are.
also RIP Kinger cuz that "thanks for everything" was the biggest death flag I've seen in a while LMAO also something something biblical reference