with over power magic and knowledge, it'll be easy to make a tool to detect devil that disguise in human form. well it'll be easy if you know them from the start right (=・ω・=)
If he can swap things around, I wonder if he could steal the hero's skills, and use them? He'd be pretty op if he could steal skills from enemies, and amass them until he became practically a god.
this is why I don't like naive people. stoping his friend to attack, told the enemy to surrender and hope the enemy will say, "ok, I'm surrender" and then the enemy got away and they bring somethings more troublesome. . . (〜 ̄△ ̄)〜
"...aargh, I've never seen tension up used like that before either!"
asley : "huh, you're the archmage, right? (smirk) ╮( ̄▽ ̄)╭