I JUST tried this strategy against Aya and it seemed to go off without too much difficult. Just a few super potions required to do so. The strategy, in brief, was to use Cofagrigus's Telekinesis to allow my Spiritomb to put the enemies to sleep with Hypnosis so that it could use Nasty Plot, as Cofagrigus would drain Aya's hyper potions by using hex on the sleeping foes. Once Spiritomb was "fully charged", so to speak, it could use Dream Eater to restore health and Shadow Ball to take care of everything else. At the time, this was my team: Spiritomb lvl. 41 Infiltrator (holding the Zoom Lens) Nasty Plot, Hypnosis, Dream Eater, Shadow Ball Cofagrigus lvl. 43 Mummy (holding the Quick Claw) Hex, Will-O-Wisp, Telekinesis, Shadow Ball The rest of the team didn't do any fighting, but here were their levels: Unfezant lvl 43, Mawile lvl 44, Arcanine lvl 44, and Sceptile lvl 45 Again, this was the double battle against Aya