So here's my take on it. He's still alive and will show back up out of nowhere in a brand new clone body since Garlemald has perfected cloning technology and even Emet-Selch had multiple cloned bodies just laying around for him to use when he died. He will be satisfied with the fight we had, but now it's no longer about having the best fight every. It's now about winning that fight as he views it as overcoming the one challenge he as ever had in his life. A goal he can aim for. In order to do this he will journey around the world in our company and help us in the new challenges we will face. If he and his method did not work in beating us, maybe seeing how we live our day to day life and following what we do is the key to finally pushing past his limits.

Yeah, it's dumb, but no one dies in this game when they should.