Questions & Mysteries Will Luffy gives his hat back to Shanks
What I expect, even if it is terribly expectable, is that Shanks fight with BB (or some other final villain Oda brings out of the hat at this point), Shanks loses and is killed, Luffy arrives soon later when there is only Shanks corpse, he leaves the hat, touching moment, then proceeds to go fight BB (or maybe BB escaped and Luffy has to find him so that the final baddie can heal his wounds). Eventually the hat is passed to Shanks son or any other possible Roger of the next gen.
Or, since Oda is now in full clown mode in more ways than one:
Luffy finds the defeated Shanks, who is dead, he gives back the hat but we discover the hat is magic and it resurrects Shanks, also at the same time fusing with Luffy's rage it unlocks gear 6: Luffy now can become a looney toon like with G5 but can also reality warp toon hammers, toon black swords, toon stuff in general, warp himself and reality too. He also resurrects Ace, WB and every other character named or not named seen in OP down to the bandit guy eaten by the Lord of the coast.
Or, since Oda is now in full clown mode in more ways than one:
Luffy finds the defeated Shanks, who is dead, he gives back the hat but we discover the hat is magic and it resurrects Shanks, also at the same time fusing with Luffy's rage it unlocks gear 6: Luffy now can become a looney toon like with G5 but can also reality warp toon hammers, toon black swords, toon stuff in general, warp himself and reality too. He also resurrects Ace, WB and every other character named or not named seen in OP down to the bandit guy eaten by the Lord of the coast.
