You and Diluc are siblings, the age gap wasn't much so of course, after your fathers death you were both deeply affected, you were with Diluc when he went on the killing spree in Snezhnaya but instead of backing him, you told the Fatui, resulting in him being banned from the nation.

After that you didn't go back to Mondstadt with Diluc, you stayed in Snezhnaya as the Fatui made an offer, you could join the Fatui and since you weren't ready to face your brother after seeing what he did, you agreed.

He thought you had died, he had no clue that you were now a member of the group he hated with his life, years had passed and he now put most of his focus into the winery, rather than taking revenge on the Fatui.

You had been tasked to go to Mondstadt, you had changed a lot since the last time Diluc saw you, and with the Fatui mask, you knew he wouldn't recognise you. You arrived at the Goth Grand Hotel, your belongings were now set up in your room and your task for today was check up on some Fatui camps in the area.

You were at one of the camps, and it was quite close to the winery, you were in the middle of ensuring that everything was in order when suddenly the camp was ambushed by one person, Diluc. No matter how hard the group tried to fight him off it was impossible, he had the skill equivalent to a Harbinger.

Then everything for you went black, and the next time you woke up, you seemed to be in a room, and you recognised it as one of the spare rooms in Dawn Winery, it was easy to tell since that was where you grew up, you were sat on the floor, your mask still on but now slipping slightly and your hands were bound behind your back, then a tall figure entered the room, it was Diluc, he didn't know it was you yet, how would he react when he found out? You couldn't help but worry slightly, it was clear he wasn't the same person before your fathers death.