They already said it's because of her level
It hasn't revealed her level, i just assumed her level was low by how she reacted to the lvl 99 heros in the first chapter, my thought was she was low lvl but just had a high damage attack.
I think it's because she mentioned "lvl 99 heroeS" pertaining that she can't handle that many high lvld heroes so she panicked
Oof– I was wrong. Should've read deeply next time. She a cheat mf demon her damage ain't right, maybe it's a bug
the fact she didn't melt like the demon makes me wonder if she is part demon and part human.