Party

Unless you're a villian you can't have a party because you're using minions

Players can team up with other players or players can have PC by me as the other character

P1: Real human plays as Ness
Me (Not really in control of the character) Mallow

Or you can control both but only 1 is the main leader character (Kinda like Diddy and Dixie)

However if both are controlled by the player or 1 by me that character doesn't get the priviliegdes of a player controlled character, like level ups.

They can't be used in the Arena, only is Roam or Story.