I can't be bothered to link pictures but I actually do have a team for him! they're not really symbolic since they were more like "what he'd have as an actual team as a trainer or something" but yeah

Banette: "Strong feelings of hatred turned a puppet into a Pokémon. If it opens its mouth, its cursed energy escapes."
ABANDONMENT AND LONELINESS ISSUES.JPG creepy doll spite-and-vengeance-powered pokemon is right up his alley. also lol non-talkative jokes
Mismagius: Hat ghost. Also a mischievous fucker. "Its cries sound like incantations to torment the foe. It appears where you least expect it."
Honchkrow: Nice hat head honcho bird. "If one utters a deep cry, many Murkrow gather quickly. For this, it is called "Summoner of Night." Do I really need to go into this one
Scolipede: This doesn't represent anything, he just likes bug pokemon and Scolipede is one of his favourites. Though I guess he does share the whole 'relentlessly and mercilessly attack targets until they're dead' thing.

"With quick movements, it chases down its foes, attacking relentlessly with its horns until it prevails." Also horns!!
Malamar: Upside-down hypnotism squid?? "It wields the most compelling hypnotic powers of any Pokémon, and it forces others to do whatever it wants."
Porygon-Z: Glitchy data implied to be kind of a failed experiment in its purpose. "Its programming was modified to enable it to travel through alien dimensions. Seems there might have been an error..."

He can mega evolve his Banette and his mega evolution item is the Mega Collar. The stone is set into the metal. Very stylish.