I am fan of every nonCaster who makes it past level 10 secretly being a member of a magical or divine bloodline or having absorbed enough magic throughout their career that their bodies are magical or purposely just went through enough processes in magical or out chemical means that their bodies are now completely upgraded.Wuxia sword saints use their chi/ki to do mystical things, more akin to monks. Hercules was a demigod. And high level warriors already have multiple attacks. Yes we tell these tales, but each tale still has a bit of "innate magic" to why impossible things happen. Now if you're suggesting every warrior who takes the "divert river" ability is part demigod, I'll gladly accept it.
I know some people don't like that explanation but really there are no level 12 characters in real life so I have to go with the process that you need something extra to pass real world level cap.
I mean guzzling health potions for years cannot produce in natural body.