I’m pretty sure he is not dead. Of course it would be a good ending for his character but it looked more liked he would be teleported into another realm.
Probably the same where the wraith took Philip’s soul. I mean it could be a land of lost souls and based on that they put a lot of Greek Mythology into the show I would theorize it might be Hades, the Greek underworld.
But just the first thing witch came into my mind.
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“There were thousands and thousands of forms of joy in the world, but that all were essentially one and the same, namely, the joy of being able to love.”
— from the Neverending Story by Michael Ende