The ladder is still infatuated with Baneful Bunker despite the prevailing reason in this thread, so I'm dropping by with a PSA on what makes Protect moves work in singles:
- Aegislash is great with King's Shield because the opponent has to respect it: the alternative is Aegislash getting off a powerful Shadow Ball/etc. It also helps you change forms, makes up for your lack of recovery and beat physical attackers that rely on contact moves like Knock Off and Flare Blitz.
- Heatran is great with Protect because the opponent has to respect it: the alternative is Heatran getting off a powerful Lava Plume/etc. It also makes up for your lack of recovery and can mess with HJK users, as you're weak to the move.
- Chesnaught is pretty good with Spiky Shield because the opponent has to respect it: the alternative is Chesnaught setting up another layer or getting off a powerful Wood Hammer/etc. It also combos well with Leech Seed.
- Anything with Wish needs Protect because it's a useful two-part combo for consistently recovering.
Toxapex possesses none of these qualities, namely that no one needs to
respect Toxapex. It's much less risky to just setup/recover/etc. on the prediction than pretty much any other Protect user. Its attacks are embarrassingly weak, and even Burn damage is pretty unimpressive now, so the opponent doesn't need to respect the alternative that you may attack them. Toxapex in no way needs to compensate for a lack of recovery, as you have multiple avenues for recovering lots of health (Recover, Regenerator, Black Sludge). It's pointless in screwing with HJK users because you eat up the attack anyway. In fact, there is barely a single contact move that hits you super effectively: Zen Headbutt is literally the only one I can think of, and one of its best users (Metagross) is immune to Poison anyway. Literally the only thing you have to worry about is Scald burns, which are easier than ever to play around this generation, so there's no imperative to attack Toxapex over using another move.
Merciless has been thoroughly deBUNKed as a viable ability already, but even if it weren't, why the hell would you run Baneful Bunker on that set? Recover and Venoshock are non-negotiable because you lack Regenerator and need a high-powered move for poisoned targets. You need a method to deal with Steels and Poisons, so probably a Water move? Then you need a way to actually trigger Poison, for which you have three options. Toxic is by far the most reliable, Toxic Spikes is possibly workable if your opponent has low hazard control, and Baneful Bunker...is useless against non-contact attackers or one that simply ignore it. Even if you drop Recover or your non-Poison move for some reason, I'd still rather run Toxic + Toxic Spikes over Baneful Bunker in any capacity.
Toxapex is an amazing Pokemon if it plays to its strengths. Stop misusing it by wasting a moveslot on Baneful Bunker to become a bargain bin Aegislash.