Shedinja

Shedinja is an incredibly potent threat in the Balanced Hackmons metagame, able to endure virtually any direct hit and bring most foes down to their last breath in one fell swoop. Shedinja's almost infinite bulk comes from its unique hardcoded 1 HP stat in combination with the ability Sturdy, which allows it to tank any direct damage thrown at it that doesn't come from a Pokemon with Mold Breaker. From here it is able to use moves such as Endeavor and Pain Split to reduce the foe's HP or simply function as an extremely efficient defensive pivot to preserve your team's momentum and easily switch in checks and counters for whatever the opponent attempts to throw at Shedinja.

Shedinja has defined the Balanced Hackmons metagame to the point that any successful team has multiple ways to deal with it, most of which function very well outside of countering Shedinja. Strategies include Mold Breaker, which becomes an almost infallible way of dealing with Shedinja if paired with Pursuit. Other methods include entry hazards such as Stealth Rock and Toxic Spikes, status infliction, partial trapping moves, Rocky Helmet and Spiky Shield, and damage-dealing weather conditions such as sand and hail. A well-played Shedinja will almost always be able to nullify the effects of these methods, though, either with proper team support or by adjusting its moveset or item.