What it does
Baneful Bunker works like Protect — the user is fully shielded for the turn — but any Pokémon that uses a contact move against the shielded user gets poisoned. Regular poison, not badly poisoned. Still, that's passive damage every end-of-turn for the rest of the game.
Shared success-rate decay: Baneful Bunker and all other protection moves share the same consecutive-use penalty. Second use drops to 50%, third to 25%, and so on. You can't just cycle it indefinitely — alternating with Protect is standard.
In doubles it only shields the user, not the partner. But the threat works either way: hit Toxapex with a contact move and you eat poison; don't hit it and your partner takes full damage from the other side.
Who runs it
Toxapex at 86%. Its entire gameplan is built around a block-trap-drain loop: Baneful Bunker on one turn, Infestation to lock the target in place, then alternating protection moves while the 1/16 per turn and poison chip stack up. Toxapex's bulk makes this loop actually work — it survives long enough to see the opponent run out of options.
How to use it
Alternate Baneful Bunker with Protect to keep success rates near 100%. Once Infestation has a target locked, start rotating the protection moves. The trapped opponent bleeds 1/16 HP per turn, poison ticks on top, and they can't switch out.
Timing matters: if your opponent switches to a special attacker using non-contact moves, you lose the poison trigger for that turn. The move still blocks, but half its threat disappears. Read whether the incoming Pokémon uses contact moves before committing.
Tips & strategy
Contact moves include Fake Out, most physical Fighting moves, U-turn, and the majority of physical attacks. Non-contact moves — most Special attacks, Rock-type coverage — skip the poison entirely. Once opponents see Toxapex, they often pivot to special coverage specifically to dodge the poison. That pivot is itself useful information.
The true counter is getting a Pokémon in that bypasses both protection and trapping — Rapid Spin can clear Infestation, and pairing that with a forced switch breaks the loop. Or just bring a Special attacker that doesn't trigger the contact punishment and pressure Toxapex directly.