[Ninjavenom]

When you're on a second playthrough, just cheat and level the shit out of a majin and then transmigrate him into a cleric. Her stats will mirror that of the majin's, by percentage of what he had when you transmigrated. If you're on your first playthrough, go into the Item World and level your 3 best belts and your best sword to as high as you can get 'em and dump 'em onto her.