It doesn't have to be a combat based one it could something like seasons or a minigame based like pokeathlon.
I'll start first
Job classes: Each Pokemon can gains a job class that overwrites their ability with a park and give’s them a 10% stat increase to their stats based on their role I.e. a attack base role gives a 10% increase to your attack stat. Pokemon with base 100 or above in any stat can’t gain a role based on the stat such as garchomp being unable to gain the attack role or speed role but can use a special attack or special defense role.
Attack role: gives 10% to attack all contact moves deal additional 15% damage.
Defense role: 10% to defense and reduces damage by 15%
Speed role: speed role 10% to speed and a 10% chance in for attack moves to cause flinch. Does not stack with items or moves with a flinch chance.
Berserker role: All attacks deal super effective damage but the pokemon takes 10% recoil damage. Does not take type into account and deals 2x damage by default. All base stats must be bellow 100 to use.
Medic role: Raises SpD by 10% and status moves heal a small a 5% damage and 3% damage to adjacent Pokemon. Damage moves deal 10% less damage.
Sage role: Special attack gains a 10% buff and special attack moves gain a 10% accuracy increase. Physical and status moves gain a 10% decrease.