Or..As well as any other 20th level barbarian with a 20 strength. Which is not at all. I think you want to play mutants and masterminds with Superman instead of dungeons and dragons.
Conan is level 13-15 and not on the level of a time stopping wizard or a walking saint.
The base system of D&D often stops working after level 13 or so. That might be why old versions of the game had level caps or diminishing returns. Especially since popular fantasy of those days didn't have high level PCs. Aragorn was level 14.