[He's grateful that instead of questioning him, Diluc offers to hear him out. Aether nods and directs them both somewhere where they can sit and talk.]

It was difficult to believe at first, but it seems there are two versions of Teyvat out there - one where Lumine is travelling to search for me and one, where I am the one travelling to find her.

[A crazy theory and yet...]

It also seems like in both versions of Teyvat the events were just the same... So if you don't believe me, you can ask me of anything that only Lumine would know.