If playing Gen 9, Tera Fighting or Tera Psychic are great for pure power, while Tera Steel can help Gallade survive its Fairy and Flying-type weaknesses.
Sharpness . This is the core of this build, increasing the power of slicing moves by 50%. Gall-09rar
Because Sacred Sword ignores defensive buffs, use Gallade to shut down "stall" Pokémon that rely on Iron Defense or Acid Armor. If playing Gen 9, Tera Fighting or Tera
Life Orb for maximum damage, or Focus Sash to ensure it survives one hit to set up. If playing Gen 9
Gallade is a powerful Psychic/Fighting-type Pokémon known for its high Attack and Special Defense. In recent generations, it gained the ability, which significantly boosts its "slicing" moves.