just saw the devil goddess
and i think it could be cool to add her before you win the match
if you click summon her on a tome you could make diffirent versions of her like a hero
each ruin could give her more and more strength up to her current form
maybe she starts as a firery witch but then turns from that to a fire wolf from that to a fire sucubus then from that either to her boss form or to the vampire then the boss form