Modest Nature

Modest raises Sp. Attack by 10% and lowers Attack by 10%. At level 100 with full investment, that's roughly a 30-point swing on the boosted stat. Pokemon with Modest nature prefer Dry flavor and dislike Spicy.

Top Modest users include Gholdengo, Greninja, Volcanion, and Heatran. They benefit from the Sp. Attack boost because their main damage comes from that stat. The Attack drop doesn't hurt them since they don't rely on it.

Modest is a strong competitive nature. It's one of the most-used natures in competitive formats. The key is matching it to Pokemon that don't need Attack in their moveset.

Synchronize is the fastest method. Lead with a Pokemon that has Synchronize and Modest nature, and wild encounters match it (Gen 3+). Breeding works too: give the Modest parent an Everstone and all offspring inherit the nature. Nature Mints (Gen 8+) let you change the stat effect to Modest without rebreeding.

Modest prioritizes power, while Timid goes for speed. Pick Modest when your Pokemon's role depends on the stat it boosts. Go with Timid when speed matters more for your team.