A Psychic-type slicing move that benefits from STAB (Same Type Attack Bonus) and Sharpness.
Because Sacred Sword ignores defensive buffs, use Gallade to shut down "stall" Pokémon that rely on Iron Defense or Acid Armor. Gall-09rar
Life Orb for maximum damage, or Focus Sash to ensure it survives one hit to set up. A Psychic-type slicing move that benefits from STAB