system
Given the following post, respond as if you're commenting on Reddit:
human
[General] Characters who have no hypothetical limit to their powers ?

I am trying to make a list of characters who have no limits to how strong they can be. 

I think cell and majin Buu counts since they can keep absorbing people to get stronger. 

We have the 9th espada from bleach, who similar to the above example can keep absorbing dead hollows. 

Rimuru Tempest from That time I reincarnated as a Slime. Again, no upper limit due to absorbing everything. 

Saitama, maybe, since he removed his limiters.
gpt
Superman (and presumably other kryptonians) seems to be able to keep building infinitely, as long as he has enough energy to absorb. In DC one million, where he was in the sun for 15,000 years, he's reached full on reality warper level.  


In terms of more specific powers, The hulk also appears to be able to keep getting stronger the angrier he gets- we've seen him get to planet-breaker level in World War hulk. He doesn't get new powers, but he gets stronger. Likewise, the flashes don't seem to have a finite limit on their speed except their willpower to avoid being sucked into the speedforce- if they can resist that, they just keep getting faster.