1. Mithos is made completely of magic! I, I DON'T KNOW HOW TO CLASSIFY IT AS TYPE. It makes him 'inorganic' and it's powered by dead souls! Details are listed here if that will help. There is a flavor of light elemental to it because that seems to come with being an angel, but it is a pretty complicated thing.

2. Dedicated mage/bizarre magic thingamajibbet as mentioned in 1!

Fortunately I don't think we will have to go 'WHAT IS EVEN GOING ON HERE' too often because I don't think Mithos winds up needing healing from other parties that much.