UllarWarlord
I give you boyfriend the male Psyduck.
Boyfriend always gets mental problems whenever his health drops into yellow range or he gets inflicted with poison, burn or confusion.
To calm down he needs to use WaterSport immediately.
If he cannot, you have to switch him out and keep him out of the battle. (WaterSport=0 PP or your boyfriend fainted)
As soon as boyfriend evolves, he remains calm in any situation.
But because he wants to impress Misty he may now only use WaterPulse as an attacking move in battles.
He needs to defeat (but not solo) at least four GymLeader owned Water type Pokemon to show his superior qualities.
Afterwards boyfriend may use any move in battles.