Haven't tried it but you'd definitly need all evolutions at max level as well as bunch of full heal and buff items. buffs are really op in this game. Going red slime might be a good idea since the boss takes 6 turns in a row later on and you can hit him back every time he attacks making it much less of a one sided advantage. No idea tho, he seems too op for one monster to deal with, especially when you can easily hit 70k dmg in one hit as Mage at lower level. The bottle that says in the description causes knock down also additionally lowers DEF so maybe there's one that lowers ATK as well which could be crucial