Lol healthy Cain is pretty much a myth at this point, I don't think hes been healthy since 2012. I honestly see Cain as retired and don't think he should come back. His last injury was obviously incredibly severe, to pile on to his list of other severe injuries.
Seems like the smart thing to do would be to save what's left of his brain and hope it's still there once his body gives out on him and he ends up like Mark Coleman is nowadays in his early 50s.