Malefor is a relatively simple boss, a few melee attacks a few ranged attacks, nothing special really. For almost every battle all you need to do is have the Lightning Sphere thing and use that to attack him. Because then you will damage him and if you hit a particular area on him, (I haven't exactly figured out where yet, I think it's either his wings, chest, or back), then you will get all kinds of gems, including health and mana gems! Meaning that as you use up your mana you will hit that particular spot on him and regain the mana you lost. This does work!! I just used this tactic to beat the game for the first time!