I recently beat him with a team of Meowstic, Pachirisu, Kricketune, Koffing, Roselia, Loudred. Obviously, Meowstic is the MVP here. And I took Crobat out with Koffing's selfdestruct.
My hardest battle is Kiki. I still having trouble defeating her though I have Granbull and Meowstic on my team.