Kinda don't feel like he died..I feel like he used a transportation spell on himself to send him somewhere else like how Ergon got his egg. Keep in mind although they said Arya found the Eldynari, it couldnt been the ones he (the King) was using cause they wasn't on him or at least near him.. Bast had his in his armor, Ergon kept his in a pocket of space behind him and even Murtagh gave his up indicating he had them on him. I have more thoughts on this matter and others in 2019 is this still a active topic?