Yusuke is an artist above all else. He's always looking for the beauty in his surroundings, even while on the job as a Phantom Thief. Art seems to be on his mind almost constantly.
His Persona gives him the ability to perform ice-based attacks, so he's our Ice-type Gym Leader. Given his sometimes cold and nonchalant demeanor, Ice-type Pokemon were made for him. Most of them are aesthetically pleasing to look at too, which I'm sure he'd love.
Here are the six Pokemon that he'd have on his team: