Her devil fruit let's her imagination become her power.
Yo if thats the case then don’t you think it’s a legendary power like luffy? Damnnn
I think that's why the government wants her. Other than the fact that she was one of their sick experiments.
wasn't her devil fruit got the power to change her age? (⊙…⊙ ) damn
That was her ability while she was still "learning" how to use it. And more than aging up or down, it was moreso that Bonney "wanted and wished" to be a certain age to either escape danger or go out to see and look for her dad. So in that aspect, her ability to age up or down still aligns with the ability to bend reality/power of imagination.
Think of it like bending reality/transforming into a copycat Nika is an evolved and better utilization of her powers whereas merely aging up or down is just 5% of it.
Luffy helps freeing her. He's the embodiment of the God of liberation n freedom. Remember, she asked Luffy "how" and Luffy helped her
why bonny turned into nika ???