Finished my app I think. He's a purely magical being anchored to a giant (headsized) diamond gemstone. In the longterm, nothing will kill him or permanently damage him because he's made up entirely of spells- so many that you'd never be able to dismantle their structure or tear any of them apart before they're reformed. Think of a super-intelligent AI that may have developed self-consciousness, except instead of coding and programming, it's magic.