I don't think it's "obvious that he's also reeincarnated", it doesn't make sense to me, Lippe reeincarnated because that entity was amused with her song and decided to reverse time for her. Well, there is still time for explanations.
This chapter was hard to understand during the flash back. I can't tell who was talking and saying what. Everytime i think i got it, something doesnt seem right later. Ugh, sadness.
I dont remember if its true but if I'm not wrong he had a dream about the past...He didnt rlly reeincarnate...Maybe that entity wanted someone powerfull to take of Lippe, who knows