What would make Isabelle different from the rest of the cast, I'm a big AC fan myself, but I never got to buy New Leaf. ;-;
Well first off, Isabelle's occupation is that of secretary, seeing as you're now the mayor of "Name your town here" and you decide what goes on. Isabelle would be a planner and co-ordinator, but not in the sense of a tactician like the Avatar of Fire Emblem Awakening. One of her biggest jobs in New Leaf is helping you set down new Public Works projects, which are new attractions for your town. A standard B move could be setting down foundation for a new works project and by holding B, the bigger and bigger the foundation will be, kind of like Peacock's Look out Below from Skullgirls. The minimum could be that of a Park Bench, while the max could be that of Brewster's cafe.
Using Ordinances, you could change certain things about your time to excell more than others. For example, the Night Owl Ordinance let shops stay open longer and later and your residents went to bed at later times. Ordinance can be a down B counter than can boost Isabelle's stats for a short amount of time. A few other things that could be included are party poppers that are used as celebratory items for your project's completion, singing a Town Tune, and one thing that I think can be really nice but hasn't been used yet, which is sad, which is the assistance of other residents. In New Leaf, it's all about living together as one to help make your town the best it can be, and if you need each other to help with different things, why not show that in a moveset in which some of the residents of Animal Crossing come out to help? As for a Final Smash, the most important thing and first thing you do as Mayor in New Leaf is plant a sapling in the plaza, which symbolizes your growth as Mayor, and Isabelle can plant the sapling which can then grow into a gigantic tree. And of course, that's just one possibility.
There's alot of things I can pull from to design a moveset for Isabelle.
