Level 100 Statistics (see level 5, 50, 100)
Rain teams are a powerful force to be reckoned with in 4th Gen UU, and it's no accident that Gorebyss is a common feature on most of them. Its praiseworthy Special Attack and its ability to outspeed the entire tier in the rain make it a dangerous foe to face. Gorebyss can even function as a successful Baton Passer when rain is not in play. Despite less-than-stellar base HP and Speed stats, Gorebyss remains a serious threat for an unprepared team.
With an admirable base 114 Special Attack stat and enough Speed to outpace any UU Pokemon with Swift Swim activated, this South Sea Pokemon makes an excellent rain sweeper. Hydro Pump is Gorebyss's most powerful STAB attack, capable of OHKOing or 2HKOing almost anything that lacks a resistance or immunity to it. Surf is also an option for more accuracy, though it lacks the raw power of a rain-boosted Hydro Pump. Ice Beam complements Gorebyss's Water STAB nicely, landing super effective hits on the annoyingly ubiquitous Grass-types. Hidden Power Grass allows Gorebyss to cut through opposing Water-types, creating nigh-unresisted coverage in UU. In the last slot, Psychic is used to eliminate Toxicroak, Poliwrath, and Qwilfish, the former two of whom sport abilities that give them immunity to Water and would otherwise create endless amounts of trouble for a Rain Dance team.
Team Options & Additional Comments >>>
This set lets the pink menace take a more supportive role as a Baton Passer. Although Gorebyss has a plethora of moves it could pass, Agility is the most effective, allowing a teammate to reach blistering levels of Speed for a lightning-fast sweep. Substitute safeguards Gorebyss and the Baton Pass recipient from harmful status effects, in addition to providing cover from incoming attacks. Finally, Surf ensures that Gorebyss isn't rendered a complete deadweight by Taunt, since even with only a meager investment in Special Attack it still hits decently hard.
Team Options & Additional Comments >>>
Gorebyss has very few options outside of these specific niches. Turning Gorebyss into an Agility sweeper is possible, but it lacks the raw power of the rain sweeper, and will still fail to outpace Choice Scarf Rotom. On the Baton Pass set, passing Aqua Ring, Iron Defense, or Amnesia instead of Substitute is possible, but it is an inferior option. Shadow Ball and Signal Beam round off Gorebyss's special movepool, but they are highly inferior options to its other attacks.
Checks and Counters
When utilizing the Swift Swim Sweeper set, Gorebyss's true counters are sparse. Specially Defensive Milotic can work if Gorebyss is carrying a Life Orb, as it can cripple Gorebyss with Toxic or KO it with Hidden Power Grass while healing off damage with Recover. Toxicroak also poses a problem if it switches in on anything other than Psychic, as it can KO a weakened Gorebyss with Sucker Punch. Ludicolo is a dire threat, since Gorebyss has nothing that can even hit Ludicolo for super effective damage (outside of Bounce), while Ludicolo will always OHKO back with Energy Ball. One of Gorebyss's greatest fears are priority moves, which can quickly wear it down to KO range. Rotom, the most common UU Choice Scarf user, is also one of Gorebyss's most common checks, since it will always outspeed Gorebyss with a Timid nature. Positive nature Choice Scarf Venusaur and Electrode do likewise, while Registeel can survive Gorebyss's onslaught and cripple it with Thunder Wave.
The counters list for the Baton Pass set is much less specific. Phazers can cause problems, as they mess up the Baton Pass chain and negate Gorebyss's boosts. Haze Milotic or Weezing also stop Gorebyss from doing anything productive. Taunt prevents Gorebyss from passing on its boosts or setting up, leaving it a veritable sitting duck, well, fish.