[OVERVIEW]
Gorebyss has a great boosting move in Shell Smash, an impressive base 114 Special Attack, and a great offensive movepool with such as ("with" is fine here; using "such as" implies examples of movepools, which is not being done here) Hydro Pump, Ice Beam, and Signal Beam, which makes it a threatening sweeper. Gorebyss also has have ("has" is correct here; the analysis isn't referring to all Gorebyss, and is therefore singular) access to Swift Swim, making it really dangerous in the (weather conditions usually aren't preceded by "the") rain. Due to its low Speed stat, Gorebyss also fails to outspeed Choice Scarf Rotom and Rotom-S even at +2, making it vulnerable to being revenge killed, and . Gorebyss also has a hard time setting up against various Pokemon and against offensive teams. (period) due to its poor Speed stat. Gorebyss also has a mediocre lacks special bulk, making it hard to set up against powerful special attackers such as Rotom, Lilligant, and Ludicolo.
[SET]
name: All-Out Attacker
move 1: Shell Smash
move 2: Hydro Pump / Scald
move 3: Signal Beam / Ice Beam
move 4: Substitute / Hidden Power Grass
item: Life Orb
ability: Swift Swim
nature: Modest / Timid
evs: 4 Def / 252 SpA / 252 Spe
[SET COMMENTS]
Moves
========
Shell Smash boosts Gorebyss's Special Attack and Speed to high levels by two stages. , making it a terrifying cleaner. Hydro Pump is Gorebyss's strongest STAB move, which (fluff) hits really very (sounds better) hard after a Shell Smash boost. On the other hand, Alternatively, (good change!) a more reliable, yet weaker Scald can be used, which has a 30% percent chance to burn the foe. (period) , denting the opposing team. Signal Beam is used to KO common Gorebyss switch-ins such as Ludicolo and Jynx,(remove comma) as well as KOing Malamar. Ice Beam lets Gorebyss deal with Grass-types, such as Vileplume, Gourgeist, and Roselia, which otherwise wall it. Substitute can be used to block status ailments, and letting Gorebyss destroy stall teams. Hidden Power Grass lets Gorebyss deal with Water-types, such as Lanturn and Prinplup.
Set Details
========
Maximum Special Attack and Speed maximizes (try to avoid being redundant with your diction) enhances Gorebyss's power and Speed in order to allow it to sweep the opposing team. Life Orb is used to increase Gorebyss's damage output at the cost of HP with each attack. A Modest nature is used to maximize Gorebyss's Special Attack. However, a Timid nature can also be used to further increase its Speed, which makes Gorebyss outspeed Jolly Cacturne, Exeggutor,(add comma) and Aurorus before a Shell Smash boost, and Jolly Choice Scarf Sawk, Jolly Choice Scarf Pinsir, and Timid Choice Scarf Mesprit after a Shell Smash boost. If Gorebyss is running Substitute, it should run 152 HP / 132 SpA / 224 Spe EVs with a Modest nature to stop Gurdurr from breaking the its Substitute by with Mach Punch. (period) Gurdurr. (great changes here)
Usage Tips
========
Due to Gorebyss's low Speed, it cannot set up a Shell Smash on most Taunt users, (AC) of Taunt, such as Archeops and Mismagius. However, once Gorebyss gets to +2, it will outspeed the entire unboosted metagame and certain Choice Scarf users, though it still fails to outspeed Choice Scarf Rotom, Lilligant,(add comma) and Rotom-S. Gorebyss should use slow, (RC) defensive Pokemon such as Rhydon, Carracosta, Gourgeist, and Weezing for as setup bait by forcing them to switch out,(remove comma) as well as Choice-locked Fire-types such as Pyroar. If necessary, Gorebyss's decent physical bulk and good defensive typing allow it to set up on various offensive Pokemon, although it should not set up on specially offensive Pokemon, due to its poor as it lacks special bulk. Gorebyss should be used as a late-game cleaner; when the opponent's team is weakened,(add comma) so that Gorebyss can set up easily.
Team Options
========
Gorebyss appreciates Pokemon that can take Grass- and Electric-type attacks aimed at it, such as Magmortar and Rhydon, respectively. Dual screens support from Uxie makes it easier for Gorebyss to set up a Shell Smash. Uxie can also use Memento to make it easier for Gorebyss to set up. Uxie, Liepard, and other Rain Dance users can aid Gorebyss by triggering Swift Swim. Uxie can further aid with Memento, (AC) (This seems redundant because it was already mentioned that Uxie has Memento.) (yes, it is redundant) while Liepard can use Encore on the target and then U-turn to Gorebyss, giving it an easier time to set up and sweep.
[SET]
name: Choice Specs
move 1: Hydro Pump / Scald
move 2: Ice Beam
move 3: Signal Beam / Hidden Power Grass
move 4: Baton Pass
item: Choice Specs
ability: Swift Swim
nature: Modest
evs: 4 Def / 252 SpA / 252 Spe
Moves
=============
Hydro Pump has great power when paired with Choice Specs, dealing (good fluff removal!) deals a lot of damage great damage to anything that does not don't ("does not" is correct; read it out loud and you'll see :) resist it. Scald can be used over Hydro Pump for a more reliable move, as well as the 30% percent chance to burn the target. Ice Beam lets Gorebyss deal with Grass-types, KOing most of them, such as Torterra and Vileplume. Hidden Power Grass lets Gorebyss deal damage to bulky waters Water-types, such as Prinplup, Samurott, and Lanturn, who which otherwise walls Gorebyss. Signal Beam is used to KO common Gorebyss switch-ins such as Ludicolo and Jynx, as well as KOing Malamar. Baton Pass is used to gain momentum,(add comma) which, (AC) (the comma goes BEFORE which, not after) gives Gorebyss a niche over Samurott. (period) alongside having a higher Special Attack stat.
Set Details
=============
Maximum Speed and Special Attack EVs let Gorebyss have maximum optimal (redundance) attacking prowess while being as fast as it can. Choice Specs makes Gorebyss a dangerous wallbreaker to the opponent foes. A Modest nature means allows Gorebyss to can hit as hard as possible.
Usage Tips
=============
Gorebyss should switch into Ground- and Rock-types,(remove comma) and attempt to KO them,(remove comma) or use Baton Pass to gain momentum. Gorebyss should not stay in on an offensive Pokemon unless it's completely necessary, because as it does not have the Speed to attack and would take heavy damage, leaving it vulnerable for a wall to KO it. Gorebyss should be used as a wallbreaker, denting walls so that it becomes easier for a sweeper to clean the opposing team.
Team Options
=============
Gorebyss appreciates Pokemon that can take Grass- and Electric-type attacks aimed at it, such as Magmortar and Rhydon, respectively. Flying-, Fire-, Grass-, Normal-,(add comma) and Electric-type sweepers are good partners for Gorebyss, (RC) because Gorebyss takes care of the Pokemon that these sweepers have tough time struggle to break through and gives them a safe switch-(remove hyphen)in with Baton Pass. Such sweepers are include Swellow, Pyroar, Cacturne, Rotom, Electivire, and Kangaskhan. Slow U-turn and Volt Switch users such as Uxie, Xatu, and Lanturn, and Xatu helps help Gorebyss switch in safely, as well as forms forming a great momentum core with Gorebyss. Rain Dance users such as Uxie and Liepard aid Gorebyss as well, boosting its Speed and making it able to outspeed most offensive Pokemon as well as boosting the power of its STAB moves Hydro Pump and Scald. Spikes users such as Garbodor and Roselia are also good because they (fluff) handle Grass-types fairly well,(add comma) and most of Choice Specs Gorebyss's switch-ins (AH) are grounded Pokemon and don't have reliable recovery.
[STRATEGY COMMENTS]
Other Options
=============
Surf can be used instead of Hydro Pump / and or ("or" works better here, as Hydro Pump and Scald won't be used in the same set, meaning it'll be one or the other. Arifeen, remove "and") Scald for more power than Scald and more reliability than Hydro Pump, but the damage output isn't much greater than that of Scald (If you mean by power, Surf is stronger than that of Scald. I'd say instead, "however, Scald is able to cripple threats with burns, and its power is lower than that of Hydro Pump.") (<- you can add this blue bit as another sentence, but implement the changes I made AKA just add "than Scald" and "more...than Hydro Pump" and delete the rest) , and is significantly lower than that of Hydro Pump. Hidden Power Fire can be used to hit Ferroseed.,(period -> comma) (flows better this way) and Hidden Power Electric can be used to hit Pelipper and Mantine. White Herb can be used over Life Orb in the first set to ensure Gorebyss's longevity and makes it less prone of to being revenge killed. Focus Sash can be used over Life Orb to guarantee a set(space)up, but it reduces the power of Gorebyss's attacks. Hydration can be used instead of Swift Swim on rain teams to prevent Gorebyss from being inflicted by any status ailments. Psychic can be used in conjunction with Signal Beam to hit Vileplume and Roselia. (What move would Psychic replace exactly? Or do you mean Psychic would be an option to use over Signal Beam to hit Vileplume and Roselia?)
Checks and Counters
===================
**Choice Scarf Users**: Choice Scarf Rotom, Lilligant, Jynx, and Rotom-S outspeed Gorebyss even at +2 and can OHKO Gorebyss with a powerful supereffective attack Thunderbolt if they carry it. (Lilligant can use Thunderbolt too?) (lol I changed Thunderbolt to something more widely applicable)
**Liepard**: Liepard's Prankster Encore allows it to lock Gorebyss into Shell Smash, meaning it can turn Shell Smash against Gorebyss, (AC) entirely, although Liepard does not like taking a Hydro Pump,.(comma -> period) (the sentence was too lengthy and awkward) but Liepard also has access to Sucker Punch, (AC) which can KO a weakned weakened Gorebyss.
**Offensive Pressure**: Most teams have attackers have little issue of trouble 2HKOing Gorebyss, making it very difficult for Gorebyss to set up Shell Smash Gorebyss to set up safely. If one cannot prevent Choice Specs Gorebyss from snagging getting (avoid words like this) a KO, preventing it from snagging an additional KO fainting another Pokemon is the next best thing. Gorebyss's sluggishness doesn't make this a challenging task. This forces out slower Gorebyss or simply damages them beyond repair. However, the defending player has to be wary about Baton Pass putting them in another unfavorable matchup. (I would talk more about the specific Pokemon that poses an offensive pressure on Gorebyss. The reader knows by now Gorebyss relies heavily on Speed first, so what Pokemon would take advantage of its Speed? I know there should be some threats that can also use Gorebyss when it's under Choice Specs. I'd discuss that more instead.) (Ok Arifeen this entire part sounds like you're explaining how to counter Gorebyss. I'm confused)
**Haze Users**: Cryogonal may survive a +2 Hydro Pump and either directly OHKO Gorebyss with Freeze-Dry or Haze away the Shell Smash boosts that Gorebyss has accumulated. Mantine can also take hits and Haze away Gorebyss's Shell Smash boosts.
**Priority Moves**: Kangaskhan's Fake Out + Sucker Punch, Cacturne's Sucker Punch, and Fletchinder's Acrobatics damage Gorebyss heavily after a Shell Smash, (AC) and limits limiting its sweeping capabilities. Priority attacks from Kabutops and Gurdurr won't deal much damage, however.
**Bulky Water-types**: Ludicolo can survive a hit from Gorebyss at +2 and can KO it with Giga Drain, but loses to Signal Beam. Lanturn resists Gorebyss's main STAB moves and can cripple it with Thunder Wave or heavily damage it with Thunderbolt, although it must be wary of Hidden Power Grass. (period) which wears it down. Poliwrath resists most of Gorebyss's moves and can retaliate with either Focus Blast / or Circle Throw. Mantine doesn't take much damage from Gorebyss's attacks and can damage Gorebyss with Air Slash or cripple it with Toxic. (I would mention how Mantine is immune to Gorebyss's Water attacks because of Water Absorb.)