So in a few threads I've mentioned a few more stuff on how epic tier characters can go all the way up to planet/star level. Never actually posted it in this thread (bad habit of mine lol), but better late than never I guess.
So other than the whole deal with godly avatars scaling to the leviathan, which can destroy the planet if awoken, epic level characters can straight up fight Allabar, who is a literal planet.
Furthermore, epic characters can fight against Lolth herself. It's also explicitly Lolth's true form, as her aspect is given an entirely different (and much weaker) statblock.
This isn't the only time epic characters are able to fight and defeat legitimate gods, as 4th Edition's
Last Breath of the Dragon Queen module in Dungeon Magazine (itself part of the
Scales of War adventure path) pits the party against Tiamat herself.
The beginning of the adventure even clarifies that this isn't an aspect or avatar, but the real deal, even stating that Tiamat is at the height of her power during this time.
Since the power level for gods varies from setting to setting, and 4th Edition doesn't
have a distinction between lesser or greater gods, it's safer to go off the star level feats associated with lesser gods, posted earlier in this thread. Though many deities who are often greater gods were slain within the Dawn War, such as Nerull and Io. Said deities were also slain by other deities, primordials, or even demon princes (such as Orcus, Demogorgon, and Rimmon slaying the god Amoth, or Yeenoghu slaying Gorellik). So epic level characters at their highest end are likely star level+ to
maybe universe level. This should also scale to demon princes within the Nentir Vale, overall bringing in another big boost.