I know the popular theory is Bubble is Abel but I think Bubble is an extension of Caine and his inner/critical/intrusive thoughts. I think you can point to many examples throughout the seasons to prove this:
"You swear now? Since when do you swear?" A common frustration the circus guests have being censored and while Caine cant show frustration for the system he is in, Bubble is an outlet for that.
"No thanks I'm trying to quit." Sillier, because we are talking about a pipe that blows bubbles, but if we are talking about addiction here, this could still speak to Caine trying to change a behavior he founds harmful in himself.
"You should die-THROW A FUCKING BEACH PARTY" A little slip of self-hatred there, bubble literally glitches and resets to give the rest of the line. Not uncommon from my own passive suicidal ideation.
And I think most obviously is the sequence from the most recent episode where Bubble is speaking every insecurity Caine has ("You really were the lesser of the two") into the open to the point Caine has to pop every version of Bubble that pops up as they speak. I read all of these as intrusive thoughts and Caine literally pushing (popping) them away and replacing them his own (questionable) reasoning. (The humans are ungrateful, I am all powerful, they have no choice but to listen to me)
This does open the question of where Bubble comes from and Im not completly throwing out that they are from Abel and Abel's consumed coding, but i think its more likely they are a conjuring of Caine.
