Level 100 Statistics (see level 5, 50, 100)
Gorebyss was hit the hardest by the Shell Smash + Baton Pass ban. With her main strategy outlawed, she had to change tacks to keep her head above water. Fortunately for the pink fish, Shell Smash allows her to be an excellent special sweeper in her own right. A base 114 Special Attack stat gives her attacks plenty of punch, and after a Shell Smash, she can be quite intimidating. As she commonly carries Life Orb, she must be wary of residual damage, which can make it difficult for her to sweep. She is also somewhat frail, and taking an attack while setting up can see her sweep cut short by Life Orb recoil. She does need a little support, but under the right circumstances, Gorebyss can be so utterly devastating that her victims will be left curled up in a dark corner, traumatized and reduced to tears, a mere husk of their former selves.
After one Shell Smash, Gorebyss becomes an extremely potent sweeper. She has almost perfect coverage in three moves, and few Pokemon can stand up to her onslaught. Surf is the main choice of STAB move, as it is both powerful and accurate, but Hydro Pump can be used if one feels that more power is needed. Ice Beam is a staple of any Water-type sweeper, and it allows her to blast through Grass- and Dragon-types that resist her Water-type STAB move, such as Tangrowth, Roselia, and Druddigon. Hidden Power Grass is the most useful choice for the last slot, as it can OHKO or deal significant damage to foes that could otherwise wall Gorebyss, such as Quagsire and Lanturn. Ferroseed walls Hidden Power Grass variants, so Hidden Power Fire can be used to fry it instead. However, Hidden Power Fire has little use outside dealing with Ferroseed, so Hidden Power Grass is usually preferred.
Team Options & Additional Comments >>>
Shell Smash is Gorebyss's defining niche, and she struggles to differentiate herself from other Water-types outside of this role. That being said, she does have a few useful options that can be used successfully. While Baton Pass + Shell Smash is banned, there's nothing stopping her from Baton Passing other things. Substitute, Agility, Amnesia—all of these can be passed to devastating effect if used correctly. Passing a Substitute is a great way to get a frail sweeper onto the field, and can be used to shield a key team member from status; this works rather well with rain support and Gorebyss's Hydration ability. Passing an Agility can work in much the same way as Shell Smash, and if the recipient is an exceptionally powerful sweeper, such as Aggron, the difference is negligible. She can also provide Defense and Special Defense boosts to a Baton Pass chain with Iron Defense and Amnesia, respectively. Rest can be used with Hydration and rain support in place of one of Gorebyss's coverage moves, but her frailty in addition to the Defense drops makes Rest hard to use effectively.
Checks and Counters
Lanturn and Quagsire are some of the best Gorebyss counters available. Both have access to the Water Absorb ability, and they resist all of Gorebyss's attacks except Hidden Power Grass. Lanturn in particular can fry Gorebyss easily with its Electric-type STAB moves. Mandibuzz is bulky enough to take a Hydro Pump and force Gorebyss out with Whirlwind, and with a few turns of Life Orb recoil, entry hazards might just KO her next time she switches in. Paralysis absolutely ruins Gorebyss, and Pranksters, such as Murkrow and Cottonee, can check her confidently. Priority can KO Gorebyss after the Defense drop from Shell Smash, and Entei, Hitmonlee, and Absol can all check her mid-sweep.