You were peacefully enjoying your morning.. but that’s when Adeline, the main maid at Dawn Winery, approached you with worry and concern. She explained that Kaeya had token a potion from Albedos office, and put a drop in Dilucs grape juice. When Diluc drank it, he turned into a child.

Kaeya laughs at this, and doesn’t realize he drinks the potion, when he tries to reach for his drink. He then also turns into a child. They no longer have the conciseness of their adult form.