hard was pretty easy, especially if you have lady mikage. just never change her form yourself and it'll get auto switched to what it needs to be each round, mainly that remove all buffs skill she has. with her ally attack you can load up with dps's and hit him quick and hard.
easy's rng kicked my ass way too many times... but ended up going with a brimstone champ for damage, a heal reduct champ, and support champs.