Watch your health, especially when you are battling against a strong opponent. Match as many health combos as possible, as well as using lots of potions. Also consider having poison antidotes ready. You have to either cure your poison status or quickly complete the level before you end up dying.

Health potions can be used at any time, but are best saved. When possible, allow your character to recover without them and only use health potions during difficult fights.

Upgrade health potions as soon as possible. Although this will be expensive, it allows them to recover more of your health.