Additionally, the Electric Shock spell is extremely useful against it. And Angel and Devil Milk heal for 10 I think (twice as much as stamina drink, half as much as stamina drink +, but much easier and faster to get). Really though, you might need to just get higher stats... Res in particular, but also Mys and Str. Oh, and going into the battle with buffs may help (eating food, getting a massage, going to the span or watching a strip show for example will all provide a bonus to useful stats).