@Shiroyru
Ngl, Doffy bros really have bad theories for him returning to the story
1. Doffy becoming a Holy Knight:Even for Oda this would just be sloppy nostalgia bait, it would brush over the betrayal and resentment Doffy feels towards the celestial dragons since he was like 8 years old, and that the Celestial dragons have a mutual dislike of Doffy/Homing. Though with the precedent of Dorry and Broggy ending their century long duel to be tour guides, who knows
2.Doffy being CG: This isn´t as bad, but it would require Doffy to play second fiddle to the OG members, and tbh, Doffy is unironically to narcissistic to play Tsundere for Buggy. Ironically despite being a big underworld guy, he doesn´t really have a underworld sensibility like Crocodile(remember when he dropped Disco like a dumbass because he wanted to go all in on Smiles?)
3: Doffy turning into a good guy: This would just be too far. I don´t feel like I need to explain. Part of the reason why people like Doffy is because he had a horrible childhood, and yet he´s still an evil character and no one was trying to redeem him.
Why not just create a new character from his family as a Holy knight? It would at least be trying something new.