kk no one has actually done this to my knowledge and since i am incapable a writing good stories i am suggesting a harry potter/one piece crossover
which the strawhats(after timeskip plz) somehow get to hogwarts one way or another during 4th year but get invited to participate in the triwizard tournament
as well. the champion is luffy plus he is 19 after the timeskip so he can pass through the age barrier no prob plus he wants adventure so yea
the rest is all up to you
plz review AND private message me!