Original ideas

[The Riddler]

Terrible, terrible reasoning.

Waluigi, even if made so that he could be Wario's partner, has not been in any game that wasn't a spinoff. He hasn't been in ANY storyline that was important to the series. Daisy, however, has been. Neither would be good candidates for the game though, besides, Daisy is technically in the game already.

[QingXin]

Pokemon Trainer:
- Squirtle (Water Gun, Withdraw, Waterfall)
- Ivysaur (Bullet Seed, Razor Leaf, Vine Whip)
- Charizard (Flamethrower, Rock Smash, Fly)
- Croconaw (Bubble, Bite, Water Spout)
- Meganium (Stun Spore, Giga Drain, Vine Whip)
- Cyndaquil (Flamethrower, Rage, Fire Spin)

Pokemon Rival
- Marshtomp (Muddy Water, Hydro Pump, Surf)
- Treecko (Bullet Seed, Iron Tail, Magical Leaf)
- Blaziken (Flare Blitz, Blaze Kick, Sky Uppercut)
- Empoleon (Hydro Cannon, Dive, Fly)
- Grotle (Leaf Blade, Cotton Spore, Frenzy Plant)
- Chimchar (Fire Punch, Ember, Heat Wave)

You choose which of the 3 you wish to use at the roster screen. So we got Pikachu Jigglypuff, and Mewtwo as stand alone and Pokemon Trainer/Rivals as the trainer types. Sweet!!