you should use hp potions and sleeping potion to win it, it is very easy
The sleep potion so do absolutely nothing- he loses a turn but I lose a turn doing it, so I gain nothing from it. The health potions, even the great ones, barely help. It does so much damage that I lose more than I just gained next turn anyway, so I only get maybe one extra turn. Plus using potions removes my ability to attack, so I am alive longer but do less damage, so by using potions I am actually less effective.