What about Roar / Whirlwind?
Most teams try to counter Cresselia with offensive pokemon such as Absol, Drapion, and Scyther, and less with defensive pokemon like Haze Milotic and Roar Steelix because when facing Cresselia, you need it out of the match as soon as possible. By just forcing it out, yes you have countered it, but with Levitate, no Stealth Rock weakness, and awesome defensive stats, it will just come back in later (however, in this current discussion, the Iron Defense passer must do it again).
I don't understand why Drapion is 29th in usage and Skuntank is 94th. Skuntank has served me as a MUCH better killer of ghosts and psychics. Even though it only has slightly higher attack and 0 HP/0 Sp. Def versions take about 3% less on average than 0/0 Drapion from SubCM +1 Mismagius Thunderbolt, the addition of Sucker Punch aids a lot in helping Skuntank come out on top. The mindgames involved with Sucker Punch, Taunt, and Pursuit put ghosts and Cresselia in a very tight position. Skuntank, like Drapion, can also outspeed bulky Froslass, Taunt, and Pursuit, allowing it only one layer every time Skuntank comes in. Explosion is probably the best move in the game, taking out bulky waters, ground types, and Venusaur (Skuntank completely stops any defensive version with Taunt, and can take anything from Venusaur, even Jolly Life Orb EQs). A set with Crunch/Pursuit/Taunt/Explosion with a Lum Berry can take out Rotom (except Specs Thunderbolt) and Mismagius guaranteed, and switch in on Cresselia more freely. Drapion has an awesome 110 base defense stat sure, but when it comes to eating ghosts, stopping Psychics, and being an overall excellent team player, Skuntank does it better.