Demon-Hunting Genius Mage

[Character Deleted.] I deleted the character I had been raising for over 5 years. To finally defeat the final boss of Demon Fantasy—the one I could never quite beat. For the sake of defeating ‘Baal’. “…I can just start over. I can do it.” And then… [Special reward has been granted!] “What? A mythic-tier trait?” The perfect opportunity had arrived. “This time, for sure!” I’ll raise the strongest mage and take down Baal! At least, that’s what I thought when— [Welcome to Demon Fantasy.] I found myself inside a world teeming with 666 kinds of demons. And I had the ‘special reward’ I just received! “…Fine. Let’s see who wins this.” I was confident. After all, I’ve been a veteran of this game for 10 years.