Well, if there's someone who likely knows about Ageha's soul slipping, it'll be Princess Hyorin. With that said, there was no trace of her in the first chapter, when he was feverish and recalling his previous life. Perhaps it's something that cannot be remembered.
I wonder what Igor thought about Ageha thinking he'll die soon. He had heard about him from Hyakka, so I guess he wasn't too surprised.
In any case, he sure gets to meet interesting people. He's got a second elf wholly devoted to helping him now. XD