Best Nature for Pachirisu in Pokémon Legends: Arceus

gamepur.com:

In Pokémon Legends: Arceus, a Pokémon’s Nature will decide what (if any) stat boosts and losses a Pokémon will get. As an example, the Naughty Nature will raise a Pokémon’s Attack stat and lower its Special Defense stat. Neutral Natures will essentially cancel themselves out, giving a boost and loss of equal value to the same stat, like how the Bashful Nature will add and take away the same amount of Special Attack points. How does this apply to Pachirisu?

Pachirisu’s highest stat is its Speed stat, with both Attack stats being tied for last place. This makes Pachirisu good for status moves like Nuzzle or Toxic in order to incapacitate its opponent. Since its Speed stat is already its highest stat, we could bump that stat up with a Jolly Nature. This would boost the Speed stat and lower the Special Attack stat, allowing us to get those status moves out faster.

Another choice, especially for a more robust Defense stat, would be to look for a Pachirisu with an Impish Nature. That would raise the Defense stat up while still allowing us to take the same hit to Special Attack from earlier, giving our Pachirisu the chance to survive a potentially devastating attack from its opponent.