Riku is going to be on edge throughout the whole ordeal. Losing his Pokémon (especially Flare) is going to be a pretty heavy blow for him given his recent focus on his own personal training over his team. As a result, he will be trying his hardest to get all three of his 'mons back.

He'll also be scoping out the castle, flinging himself into monster fights... basically, someone may want to pull him back before he over exerts himself. He'll also be swinging around a blunt, metallic weapon fashioned after Keyblades because he's a doofus.

I am totally up for team mates and new CR alike. :D I'd like to use this opportunity to the fullest.