As a Pokemon Lover myself, why not add in a couple of Pokemon to some of the challenges? Any Pokemon is welcome to be the subject of a good character elimination challenge! You might find on rare occasions our contestants trying to catch Bunnelbys and prevent them from stealing too many resources, feeding food to Munchlaxes and Gulpins, a Mudsdale Derby race, or even rodeo riding on a bucking Bouffalant! You can audition as any Pokemon you'd like. You can audition using more than one Pokemon voice too! The power's in YOUR hands in this casting call! I'll cast multiple people for their Pokemon impressions and voices. And also, please mention the Pokemon you're voicing in the audition box description, just in case you're voicing a Pokemon that doesn't say its name.
Here are the Pokemon voices that are currently voiced by other voice actors:

Cyndaquil and Torchic, who are involved in the 1st episode's fiery relay race
Munchlax and Gulpin, where any team has to feed the Pokemon they're given in order to evolve them first to win.

Machamp, which characters are challenged to wrestle with this King of the Pocket Ring.
Nidoking, where characters must avoid falling into the cracks Nidoking makes from the ground with its huge stomping.

Goldeen, which are part of a challenge where the teams have to guess which fishing pole bait shall lure a Magikarp in to have for dinner, The first team to successfully reel in the only Magikarp wins, and shall have that Magikarp for dinner in their safehouse! Whew, times like those make me feel SO glad I never have to pay the contestants a visit.

Aegieslash, in which the characters will have to guess through hidden walls which Aegieslash is in blade form, and avoid the others that are in shield form.

 Greninja, which will help different characters in a Wii Party U Ninja Scramble inspired game.  

Buizel, in which the characters have to bet on which Buizel shall win a swimming race for them.

 Quilladin, which I'm still thinking what they can do in a challenge. Feel free to add in some suggestions if you'd like! Same with the Froakie, and Squirtle. 

And a vicious Malamar, who's not part of my team, but rather someone else SO eager to take over the show, and make DARK Pokemon the main theme instead of my Jigglypuff... It MIGHT lead to an improv challenge from the contestants themselves where they will have to defeat Malamar and save me…

I’d recommend auditioning as any Pokémon you'd like that are not mentioned on this list yet, as those following Pokemon are all taken by other voice actors to voice for some challenges. Thank you!