Headcanon idea part X: The definitive theory, this is what really happened!!!
Note: Both the theory and the AU are based on episode 8.
It's possible that when Caine was eliminated, the Digital Circus itself activated some kind of safety mechanism, performing a "rollback" to restore one of its most important components: Caine himself, the very person who sustains the circus.
However, this raises an obvious question: if the system attempted to restore Caine, why didn't he reappear immediately? And more importantly, why did Bubble end up taking on the role of ringmaster?
Lacking expertise in the field, my best guess is that the restoration wasn't instantaneous. While the system attempted to recover Caine, Bubble was used as a temporary replacement to cover his absence and maintain the circus's normal operations.
This could also explain why the humans seem to remember Bubble as if he had always held that position. If Caine was previously capable of manipulating memories or perceptions, it's not unreasonable to think that the circus system itself is also capable of altering or reorganizing the memories of its inhabitants to maintain a coherent narrative.
This leads to another interesting possibility: that the Caine who appears later is not a copy created from scratch, but rather that he was not affected by the rollback since the one who created the circus was Caine himself and therefore would not be affected by this process.
The reason why, even though Caine had greater privileges within the circus, doesn't mean the circus couldn't offer some kind of benefit, like a "life preserver," for example.
And if that were the case, the most logical point of restoration would be Pomni's arrival.
After all, the arrival of a new human seems like the kind of significant event that would justify creating a recovery point within the system.
But that raises another question: if Pomni had already been in the circus for some time, why did it take Caine so long to return?
My hypothesis is that the rollback began the moment he was eliminated, but his recovery took time, which is why he didn't appear at the same time as Pomni. It wouldn't be the first time the circus has shown delays between an event and its consequences. Similar to how Kaufmo's abstraction took from episode 1 to 5 (a couple of weeks) to place the "X" on his door, Caine's restoration could have taken several days to complete.
It's not a perfect explanation, but it would at least allow us to connect Caine's disappearance, Bubble's temporary rise, and their subsequent return within the same sequence of events.
In short, I would organize the theory like this:
The circus activates an emergency rollback.
While the restoration is taking place, Bubble fills the vacant position.
The system adjusts memories and logs to maintain consistency.
The restore point used is the last autosave, possibly the arrival of Pomni.
The restoration takes time to complete, explaining why Caine doesn't reappear immediately.
This theory stems from another previously proposed one: Caine has disconnected.