What it does
Leaf Storm is a Grass-type Special move with very high Base Power. After dealing damage, the user's Special Attack drops by 2 stages.
The damage is calculated at the user's current Special Attack before the drop happens. So the first use hits at full power; the penalty is paid afterward. The second use hits at heavily reduced Special Attack — 2 stages down is roughly 44% of the original power tier. Switching out clears the drop.
Two main paths around the self-drop: First, Contrary reverses stat changes — Leaf Storm then raises Special Attack by 2 stages instead of lowering it, compounding on every use. Second, switch out immediately after using it, clearing the drop and re-entering fresh for the next use.
Who runs it
Serperior (99%) almost always carries this with Contrary. Each use of Leaf Storm raises Special Attack by 2 stages instead of dropping it. First use: +2 SpA. Hit again: +4 SpA. The power compounds in a positive loop — the more you click, the harder each one hits. Serperior with several SpA boosts becomes extremely difficult to handle from the front.
Roserade (41%) is a high-Special Attack Grass-type that uses Leaf Storm as its maximum damage output, then pivots out to reset the drop. The cycle of hit-switch-reenter keeps high-power Leaf Storms coming.
Venusaur (39%) in special attacking modes uses Leaf Storm as a one-shot nuke — fire and then switch, especially under Chlorophyll sun-boosted speed where it acts first.
Scovillain (39%) is Grass/Fire and uses Leaf Storm as its highest-power Grass coverage.
Hydrapple (29%) is Grass/Dragon and uses Leaf Storm for Grass-type special firepower.
Decidueye (13%) occasionally runs special sets where this is the Grass-type finisher.
How to use it
For non-Contrary users, the pattern is hit-and-pivot: fire the highest-power Leaf Storm available, then immediately switch out to reset the Special Attack drop. Back in on the next switch, full power available again. The cost is the switch itself — giving up a turn of action and taking any hazard or chip that comes with the transition.
For Serperior with Contrary: no pivot required. Keep clicking. Each hit raises Special Attack, the next hit is stronger, and so on. Once it gets going, the offensive pressure becomes very hard to deal with through conventional means.
In doubles, Leaf Storm is single-target. Use it into the Pokémon you most need to remove this turn. Helping Hand amplification pushes this into clean KO range on targets that would otherwise survive — ideal when you need to guarantee a KO on a specific threat.
Tips & strategy
Contrary transforms this move from a one-shot tool into a compounding win condition. Without it, Leaf Storm is a powerful but self-limiting attack — effective in a hit-pivot cycle. With Contrary on Serperior, it becomes a threat that gets exponentially harder to deal with the longer it survives. These are fundamentally different game plans.
The counter to a Serperior snowball: outspeed and KO before the boosts accumulate. Faster Pokémon, Fake Out disruption on the first turn, or spread pressure from both attackers simultaneously can all shut down the ramp before it becomes decisive.
Unlike Solar Beam, Leaf Storm works in any weather — its power doesn't scale with sun or drop in rain. That's a real advantage for Grass-type special attackers who don't want to commit to a weather strategy.