What if Shanks came back for Luffy a year later of leaving to adopt him but he found out about his new brothers?
This is a modern au, that's why shanks has a prosthesis and why I didn't mention the pirate theme of one piece, or luffys dream of becoming king of the pirates, but I like to think that in every universe he still calls them his "crew", and I keep the idea of the denden mushi because I love them.
Also, even if Shanks ends up adopting the 3 of them, Ace and Sabo still meet their father figures(White beard and Dragon) but in a different way and in a different context.
Uta still exist and she is alive, she's part of the family.
My handwriting is ass so in case if you need to see what it says:
Shanks: SURPRISE LUFFY!I decided to take yo--...?
-Luffy isn't in his seat-
Makino: Garp fired me as his babysitter when he found out that I was letting you see him.He took him with Dadan, she lives in the jungle at the end of the town--Shanks?-Already gone xD-I have to warn her about him at least.
Shanks: Anchor!where are you buddy?...owe, so sad... Well I guess I have to eat all of this MEAT all on my ow---
Luffy: SHANKS!!!WHAT ARE YOU DOING HERE :D?!?What about our promise?We decided to meet again when I became someone of renown with a future crew didn't we?
Shanks: Yeah,but I changed my mind.
Ace: LUFFY!!DON'T DISAPPEAR LIKE THAT JUST FOR SOME MEAT!
Luffy: Oh! I forgot about you, shanks, these are my brothers!
Ace: -mutter- I'm gonna kick your ass so bad when you get down...
Sabo: oh!I remember that name, mister, you gave your arm to save Luffy right?What are you doing here?
Luffy: I meet them when Grandpa throw me here, they saved me too!
Sabo: Well that's not exactly how it went but it's fine...
Shanks: (mm...Luffy's brothers=more sons)
Purupurupuru... Purupurupuru-CATCH-YA
Shanks: Hey Beck! It's me, Shanks.
Beck: Captain! It's been like 4 hours since you left to take Luffy with us!Did you have a problem finding or taking him with you?Do you need help ?
Shanks: No, I found him, he's safe.
Beck: Took you a while, are you coming home soon then?
Shanks: Well, actually, now I have 2 more problems...
Shanks: We're gonna need 2 more side kids beds...