I can't remember the name, but there was the water ability from one of the movies. That's my choice only for the symbolism of people like me being a pain in Oda's butt. Oda wants all fans to take the time and read each chapter carefully (he states taking around 5 minutes per chapter) to find as many breadcrumbs as possible. But it's a contradiction at the same time because he wants us to come short of piecing the puzzle together.
If I had to give a more legit answer...something with flight. I kinda like the mechanics of how Doffy "flies", but realistically it would have to be a zoan for flight in all circumstances.
Yeah I don’t know what ability you’re talking about unless you’re talking about the carbonation that the bounty hunters had in the episodes leading up to Stampede that was technology though? Because the mizu mizu no mi doesn’t exist from what I read? Is it the plasma or liquid metal one? I guess it’s not that important... flight would be nifty. I could always graft myself some wings... Ehhh the musculature needed to support them would be too much work. I’d need to grow a whole new body. Got it. Do a Linlin, clone/create a new someone that has wings, grow the body up, then do a personality transplant/immortality surgery. Problem solved, problem staying solved. Either find my respawned fruit or get a niftier one. Like my flames or magma. 😍
They changed the artwork/coloring. Movie 2. Honey Queen is shown to be blue like water in the original. The first few movies all have the same animation/artwork as the early episodes so there's a clear difference for only Movie 2. There's a scene where she transforms and goes through a pipe. I'll have to dig through my storage over the weekend. But Based on the pictures in the above link, they re-animated the movie to negate the water logia. Considering it's the second movie, the screenshots have modern animation. I'm too lazy to look, but this would stand out even more if it's the only old movie to get reanimated. Movie 4 had much better action, so I would want that one to at least match Movie 6's level of animation.