Hm....Pokemon gives us a lot....Pokemon have a LOT of variety to them. Jesse, James, and Meowth are competent (when they need to be). And they can provide access to a lot of their gadgets...and perhaps access to OTHER villain team tech and potential members....maybe even open doors to negotiate with the various Pokemon Teams (maybe even the spinoffs, like Pokemon Ranger, or Colosseum...or even Mystery Dungeon).
Rabbids....Rabbids have a BIG variety as well (the MarioXRabbids Crossover has many different Rabbid variants). Rabbid Peach COULD grant us access to other Rabbid characters....and if they have their tech, more for our arsenal.
Kirby? There is a LOT of magic and tech we can look into....but Kirby himself? NOPE!!! But maybe we can find King Dedede and be friends with him? And if we can find King K Rool.....we have a triple threat! Maybe we can find Ganondorf later...ZELDA MAGIC AND TECH!