Gallade @ NeverMeltIce/Magnet
Nature: Adamant (-Sp. Atk., +Atk.)
-Swords Dance (The best attack booster Gallade has)
-Thunder/Ice Punch (Depends on the type combination you want on the Flying type)
-Night Slash (I'd go with Night Slash instead for Shadow Sneak because of the power)
-Drain Punch/Psycho Cut (Drain Punch to drain the health, or Psycho Cut for Critical Hit)
*Note: If you want a priority move that KO's Ghost types, go with Shadow Sneak, but if you want more power, go with Night Slash.