If "Gall-09rar" refers to a specific , product code , or a digital file name (like a .rar archive), please provide a bit more context so I can give you the right instructions.
Jolly (to maximize Speed) or Adamant (to maximize raw damage).
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.
Night Slash provides coverage against Ghost types, while Swords Dance allows you to sweep teams if you find a safe turn to set up. Battle Strategy
A Psychic-type slicing move that benefits from STAB (Same Type Attack Bonus) and Sharpness.