>>28847236N is a part of team plasma. N is with team plasma up until the final moment of the game. N literally raises a fucking castle out of the ground at the end of the pokemon league.
He is not a rival. You are not both working together for a similar goal. He is the antagonist. Just because you want to literally drink his cum doesn't make him any less of an antagonist.
Your rivals in this game parallel your goals. Bianca/Cheren pursue truths/ideals respectively. Though they both want to be stronger, Bianca realizes that she's not strong enough and instead stays back to research with juniper.
Cheren on the other hand wants to become the champion and challenges you along the way up until the end of victory road where he admits you're stronger. These are rival characters.
N is just a coked up hippy who constantly waves his dick in your face acting like he's this majestic, righteous prophet of wisdom. That acid-tripping fuck has nothing in common with you and your goals.
N is not your rival. That gutter-trash, preachy piece of shit excuse for an antagonist the worst written character in the history of pokemon.