What about:
Gourgeist @ Leftovers
Ability: Insomnia
EVs: 252 HP / 4 Atk / 252 Def
Impish Nature
- Leech Seed
- Trick-or-Treat
- Phantom Force
- Pain Split
So the basic strategy is the following:
First use Leech Seed so stacked with leftovers you've got a good ammount of healing each turn.
Then...