Bai Yu was an ordinary homebody, absorbed in the story of collecting Clow Cards in Cardcaptor Sakura while playing Genshin Impact, when an accident suddenly struck. In the blink of an eye, she had transmigrated into the world of Cardcaptor Sakura! Even more unexpectedly, she somehow brought the characters from Genshin Impact along with her. Since she was the one who'd caused this mess, it was up to her to send them back to Teyvat. To clean up the whole disaster, Bai Yu decided to follow Sakura's example and collect Clow Cards. First things first, she needed a staff. Bai Yu's eyes fell on Aether, and she had an idea. “You're the one! From now on, you're the Guardian Beast!”
Aether was helpless in the face of this sudden arrangement, but he had no choice. After all, according to Bai Yu's “plan,” the Guardian Beast who would handle the final judgment was going to be his long-lost sister, Lumine. To find his sister as soon as possible, Aether could only reluctantly begin his life as a working Guardian Beast.
Aether: Why me?
Bai Yu: You're the first older-brother-type character I've ever liked.
Aether: Isn't that a little arbitrary?
Bai Yu: Fine. I was going through my chuuni phase back then.
(There may be some OOC moments. Sorry if that bothers you.)
