Luffy turning himself into a giant with a full body gear 3 on Elbaf or full body red hawk.
Nami using strong weather storm attacks such as the lighting and wind attacks that dragon used in east blue to free Luffy.
Robin being able to hit logia users with her haki and owning Crocodile next time she meets him instead of just lighting trebol on fire if she fights him.
Zoro having a hidden eye power such as a demon eye just because it would be funny and Oda seems to like Naruto after all Naruto was going to be Sanji's name until Oda changed it also maybe being able to turn into a demon form with more arms than the one he used in enies lobby lol..
Every straw hat having some haki ability and at least learning the main two types by the end of one piece.
Luffy passing his straw hat to Shanks kid on the last chapter and teaching him some of his moves also giving him the flare flare fruit because Sabo dies so he can teach him the fire fist attack lol.
Chopper learning new moves from the Kaido fight and getting his numbered chapter from Kaido arc from being forced to join Kaido's crew.
Franky using the sunny go as a transformer part in the his fight against the blackbeard crew member he is going to fight.
Sanji learning a comet type kick to one shot enemy ships or to do what Ace did to the ships in crocodiles arc with his fire attacks.
Sanji being fast enough to go around the entire world within a day by the end of series so that he say hello to all his ladies and being able to go to fishman island without a ship because he can just coat himself.
Jinbe having a tidal wave attack and then riding on top of it with all his fish friends in it to beat up the people that get trapped in the water after his attack destroys their ships
Jinbe taking that coating item with him so that devil fruit users can swim in the water but of course they will fight in the water which means he will still have to save them.
Jinbe making the ship and the straw hats ships go faster on water with his control on water.
Chopper being used like a horse to transport the entire crew just like a Santa type transport and learning how to sky walk like Sanji lol..
Usopp shooting poison into big mom's big mouth.
Robin using her hands to fly again but transporting the crew with her hand net ability and getting her hands on Franky's balls again with her devil fruit lol.
Brook taking over dead bodies or taking control of weak willed people to make them do stuff.
Franky making a army of robots like the kuma ones and having them beat the kuma ones.