しんりょく (Overgrow)

Overgrow serves as a powerful comeback mechanism that activates when a Pokémon's health drops to one-third or below, boosting the damage of all Grass-type moves by 50%. This ability transforms desperate situations into potential sweeping opportunities, as moves like Leaf Blade, Wood Hammer, or Energy Ball suddenly pack devastating punch when the user is on the brink of defeat. The threshold is precise—exactly 33% HP or less—meaning strategic damage calculation becomes crucial for both triggering and playing around this ability.

In competitive play, Overgrow creates interesting risk-reward scenarios where players must balance keeping their Pokémon healthy against potentially capitalizing on the damage boost. Fast Grass-types like Sceptile and Meowscarada can become particularly threatening late-game sweepers when Overgrow activates, as their already impressive speed allows them to outpace revenge killers while dealing enhanced damage. The ability also synergizes well with recoil moves or self-damaging strategies, though this requires careful HP management.

Notable users like Rillaboom and Chesnaught benefit differently from Overgrow due to their varied stat distributions and movesets. Rillaboom's priority Grassy Glide becomes exceptionally powerful under Overgrow conditions, while bulkier users can potentially survive longer in the activation range. The ability's straightforward nature makes it reliable once triggered, though its situational activation means it's often overshadowed by more consistently useful abilities in competitive formats.