(The main text has been completed, and the movie-watching extra is being written)

Please don't mind this weird introduction.

After Bai'e and the pioneers offered the "Negative World" fire at the center of the Creation Vortex, his vision went black. When he woke up again, he found that he and his deceased Golden People companions had traveled to a strange world and shrunk to the size of a 10-year-old child!

As for why, just assume it was Aha who did it.

Dumbledore: Savior? Interesting.

Wan Die: Did I say to annihilate Wan Bang Nier Doron? HKS!

Na Ke Xia: Magic↗↘Skills↘!

Bai'e: Harry, why do birds fly?

Harry: ?

Voldemort: Don't come over here!

Xiadie: (smiles slightly)