Probably Psychic. I'd start with an Espeon, using some sort of status move to cripple your Pokes. Once he's down, I'd bring out Gardevoir, spamming Calm Mind and when at mid-health I'd launch a (calm minded x4-7) Psychic, finishing off with Dazzling Gleam. Once that's down (and hopefully I would have fainted at least one of your mons), I'd bring out Delphox, crippling one of your mons with Will-o-Wisp. I would then spam Flamethrower/Mystic Fire, and when at critical health I'd use a Hyper Potion. I think I'd simply be a troll trainer, who absolutely hates your guts and tries to screw with your mind. Yes, I'm one of the things pokemon needs more of: jerkasses.