@ganteng No at the end of Hayate Combat Butler, Nagi relinquished her claim to the inheritance and estate. If anything I believe Maria the maid is the owner now, only because no one claimed ownership of the property.
@serkket you are correct, it's a duel that ends in either surrender or death, whichever comes first. Rigar shouted his surrender thus ending the duel. If he were to die after the surrender it would have invalidated the duel.
@Liquidxlax I think it is a combination of demon culture typically revolves around the idea of "might makes right" and humans are weak compared to the average demon so why is the Demon King holding back? Sounds like a weakling and a demon doesn't follow weaklings. It is this stupidity that will...
@sintas22 the rings are connected to the suit via a chain to collectively store mana, he lost two fingers but it looks like the rings hung on. That's my two cents but I could be wrong