A bit tired so sorry for any mistakes:
Diluc, after Crepus' death, went off the deep end, completely comatose when the abyss stared back. So when he left for Schneznaya he left a note simply saying Kaeya is in charge before leaving.
He never came back.
Years later, a year before traveler appears in Mondstadt, and one 12th harbinger killed(not Childe, his predecessor)killed Diluc appears on a riverbank, bloody and every bone broken, where a purple haired girl and her greenette papa find him.
Diluc can barely speak when Baizhu gets him to the infirmary, he couldn't even if he remembered how because his tongue had been split in half hot dog style by an ice-siccle, but Baizhu still heals him even as Diluc tries to claw the good doctor's eyes out.
Eventually he heals, but decides to stay with Baizhu, wanting to help the man who helped him
In more ways than one.
OMGEEE foremost I love the idea of, even after their fight, Diluc still leaves the winery under Kaeya's complete care. Something so mmghfdjghj about that.
And secondly, the idea of Baizhu collecting a band of misfits is so funny to me. I also have the picture in my head of this, like, completely feral Diluc losing his shit on Baizhu while he's trying to treat his wounds and Baizhu just laughs and shushes him (while sitting on top of Diluc to restrain Diluc (evil grin)). I think you awoke something in me good lord.
