I'd suggest any Pokes with regenerator ability,
the reason simply because lack of item such lifeorb, choice band, and choice specs, not enough fire power to take them down with 1 or 2 hit
EDIT:
most notable regenerator combo Slowbro + Blissey because they cover each other, if your team doesn't have any physical dark type who can buff up pretty sure the game will be very slow and can be last over an hour.