Having managed to win her way back into Middle, Cleo's looking to avoid going back to the downgrade pool and deal with the debris that is Light all over again. And all she has to do to avoid that is to take down Alhazad and whatever he might have to throw at her. Really, how hard can it be to take down a boss who's not even good enough for Heavy? Her Fire Rune specializes in area attacks, making the Metal Demon's defenses useless, and her natural speed, agility, and innate toughness will let her easily endure any attack sent her way, allowing her to retain her rightful place in Middle - and, perhaps, even dream of further ascents from her former ceiling.
