[That makes both eyebrows arch way up on his head as he doesn't bother hiding his surprise. He figured people wouldn't necessarily remember their time here, it being a dream world and all. But an alternate version of Teyvat where Aether's sister is the Traveler? It's both surprising and fascinating, and that mix of feelings is probably quite apparent in Heizou's eyes.]

That's... quite something! I've heard theories before about... I believe they called them "alternate universes"? But it's always sounded more like a work of fiction than anything else.

[He shakes his head with a small, amazed chuckle.] Man alive, the truth really is stranger than fiction, isn't it. And it must be terribly disorienting for you to hear.