* Nihilego's high HP and Special Defence combined with its unique Rock / Poison typing allow it to come in on and threaten special attackers such as Mega Pidgeot and Chandelure.
* Beast Boost grants Nihilego massive power after it has netted a KO or 2. Combined with its good Speed tier, it can allow it to both muscle through defensive Pokémon such as Alomomola and clean late game.
* While many Rock-types have to make do with the unreliable Stone Edge, Nihilego has access to a 100% accurate STAB in Power Gem. This lets Nihilego threaten common Flying-types, such as Mega Aerodactyl and Mega Pidgeot, as well as Scarf Darmanitan.
* Its movepool in general is pretty good, with good coverage options in Thunderbolt and Grass Knot, allowing it to dent the bulky Water- and Ground-types such as Swampert, Hippowdon and Alomomola that threaten other Rock-types.
* While its typing does allow Nihilego to check threatening Pokémon, it also leaves it with a problematic 4X weakness to Ground-type moves, meaning Pokémon such as Gliscor, Hippowdon and Krookodile can threaten Nihilego.
* Steel-types are also problematic for Nihilego, with all of them being able to defeat it one on one
* Low Defense means most neutral physical moves can easily 2HKO Nihilego
name: Offensive Stealth Rock
move 1: Sludge Wave
move 2: Thunder / Thunderbolt
move 3: Grass Knot / Hidden Power Ice / Power Gem
move 4: Stealth Rock
item: Electrium Z / Life Orb
ability: Beast Boost
EVs: 4 Def / 252 SpA / 252 Spe
* Sludge Wave is Nihilego's strongest STAB, letting it beat Sylveon and Mega Altaria that lack Earthquake
* Thunder hits bulky Water-types hard, 2HKOing Tentacruel without hazards, and scores neutral hits on most Steel-types. Thunderbolt can be used instead if you find Thunder's accuracy too unreliable. If you have used your Z crystal elsewhere, Thunderbolt is a superior option as Thunder is just too unreliable otherwise.
* Grass Knot hits the Ground-types that would otherwise wall Nihilego hard, OHKOing Swampert most of the time after Stealth Rock and 2HKOing Hippowdon. Hidden Power Ice can be used to hit Gliscor, having a 56.3% chance to OHKO it after Stealth Rock. Power Gem can be used as a secondary STAB, although it is largely unnecessary as Sludge Wave combined with Electric- and Grass-type coverage can hit most of the tier's hazard removers already.
* Stealth Rock is mandatory for any team to help wear it down over time.
* Toxic Spikes can be used over Stealth Rock, but UU has many grounded Poison-types such as Mega Beedrill, Amoonguss, Tentacruel, Gengar and Muk-Alola, all of which can easily remove it, making it a less reliable option overall.
* Maximum Speed and Special Attack EVs let Nihilego hit as hard as possible and outrun base 100 Speed Pokémon, such as Tentacruel and Celebi.
* Electrium Z fixes the poor accuracy of Thunder once, letting Nihilego OHKO Tentacruel and Empoleon, although the latter requires some chip damage.
* If running Thunderbolt, use a Life Orb instead for consistent power. A Life Orb also allows Nihilego to OHKO Swampert and Hippowdon with Grass Knot (although the latter needs some prior damage) and 2HKO Empoleon 91.8% of the time after Stealth Rock with Thunderbolt.
* Early-game, setting up Stealth Rock should be Nihilego's top priority. Finding space to set it up isn't too difficult, as Nihilego can force out special attackers like Togekiss, Chandelure locked into Fire Blast, and Mega Pidgeot.
* Once the hazard has been set up, you can focus on chipping away at the opponent's team.
* Generally the best time to use the Z move is on Pokémon that could otherwise beat Nihilego, such as Empoleon and Tentacruel.
* Don't switch Nihilego into phsycial attackers if at all possible, as its low physical bulk means even resisted physical attacks can 2HKO
* Grass-types such as Breloom, Serperior and Nasty Plot Celebi are helpful teammates to deal with the Water- and Ground-types Nihilego is weak to. Breloom can take out Blissey, and with Groundium Z Celebi can lure and kill Muk-Alola, although this will require Nihilego to forgo Electrium Z. In turn Nihilego can switch into the special Fire-, Flying- and Poison-type moves they are weak to.
* Strong Wallbreakers such as Heracross, Hydreigon and Choice Band Azmuarill appreciate the extras O/2HKOes they can attain with Stealth Rock support.
* Late game sweepers such as Dragon Dance Mega Altaria, Swords Dance Scizor and Swords Dance Cobalion also appreciate Stealth Rock wearing down the opposing team.
name: Choice Scarf
move 1: Power Gem
move 2: Sludge Wave
move 3: Grass Knot / Hidden Power Ice
move 4: Thunderbolt / Hidden Power Ice
item: Choice Scarf
ability: Beast Boost
evs: 4 Def / 252 SpA / 252 Spe
* Power Gem is a STAB move with great neutral coverage; only 3 types resist it and nothing is immune. It scores Super Effective hits on Mega Aerodactyl, Mega Pidgeot, Mega Beedrill, Mega Houndoom and Moltres.
* Sludge Wave is a more powerful STAB option that hits Grass- and Fairy-types super effectively such as Serperior, Breloom, Sylveon and Mega Altaria, respectively.
* Grass Knot hits Ground-types super effectively. It OHKOes Swampert after 1 layer of Spikes and 2HKOes Hippowdon.
* Thunderbolt can be used to hit Water-types more reliably, scoring a 2HKO on Tentacruel most of the time after Stealth Rock and a 3HKO on Empoleon. It also hits most Steel-types neutrally
* Hidden Power Ice can be used over either Grass Knot or Thunderbolt if Gliscor is a concern, 2HKOing it at worst
* Maximum Speed, a Choice Scarf and a Timid nature let Nihilego outrun Scarf Hydreigon and +1 Haxorus and Altaria-Mega, while maximum Specail Attack lets Nihilego hit as hard as possible. It also means Beast Boost will give Nihilego a Special Attack boost when it KOs an enemy, potentially letting it clean late game if the opponent's team has been sufficiently weakened.
* Choice Scarf Nihilego is best utilised as a revenge killer; its Rock- and Poison- STABs allow it to threaten the likes of Mega Beedrill, Mega Pidgeot, Mega Aerodactyl, Mega Altaria, Mega Houndoom and Serperior.
* Nihilgeo can switch into and force out certain Special attackers, such as Chandelure, Serperior, Mega Pidgeot, Togekiss and special Mega Altaria that don't run Earthquake with the threat of its STABs.
* However, aviod switching into physical attackers if at all possible, as most neutral physical moves will 2HKO Nihilego.
* Nihilego can attempt to clean late game if the opponent has no Pokémon left that resist either Power Gem or Sludge Wave, and they have been sufficiently weakened.
* Stealth Rock and Spikes help wear down the opponent's team, giving Nihilego an easier time revenge killing. Hazard setters such as Swampert, Gliscor and Klefki can set up Stealth Rock and Spikes, respectively. Swampert can switch into Steel-type attacks for Nihilego, while Gliscor offers an immunity to the Ground-type moves Nihilego is X4 weak to.
* Strong wallbreakers such as Heracross, Swords Dance Breloom, Haxorus, Krookodile and Hydreigon make for good teammates to soften up the opposing team. The former three can take out Blissey and Muk-Alola, which can comfortably wall this set.
* Checks to Steel-types are necessary. Bulky Ground-types such as the aforementioned Gliscor and Swampert are useful teammates, while Nihilego can check the Grass-types they are weak to such as Serperior. They can also check Empoleon and Tentacruel, which Nihilego can't scratch if you choose to run Hidden Power Ice over Thunderbolt.
* Without Grass Knot, most Ground-types can counter this set. Therefore, Grass- and Water-types make for good teammates. Celebi and Mantine have great synergy with Nihilego - the former can switch into the Ground-, Water- and Psychic-type moves Nihilego is weak to, while the latter can come in on the Ground-, Steel- and Water-type moves Nihilego is weak to. In turn, Nihilego can come in on the Fire-, Flying- and Poison-type moves Celebi is weak to, if they are special.
* Choice Specs gives Nihilego a great power increase. With a spread of 80 Def / 176 SpA 252 Spe with a Timid nature, Beast Boost will improve Speed, potentially letting it sweep late game. However, the Choice Scarf set's revenge killing abilities or the Stealth Rock's set's utility are preferred.
* Forgoing Stealth Rock for a simple All-Out Attacker set is a possibility, although it doesn't accomplish much the existing sets do not.
* Hidden Power Fire can OHKO Scizor that don't invest in bulk, but it doesn't do much else.
* Rockium Z or Poisonium Z can be used for a one time nuke, which can kickstart Beast Boost. However, Electrium-Z hits more notable targets.
* Sludge Bomb can be used instead of Sludge Wave if you prefer the 30% chance to Poison to the slight increase in power
* Psychic hits opposing Poison-types hard, but Nihilego struggles to make room for it
Checks and Counters
**Ground-types:** Ground-types such as Gliscor, Swampert, Krookodile and Nidoking resist both of Nihilego's STABs and can OHKO with their own X4 super effective STABs, although some have to be wary of Grass Knot.
**Steel-types:** Scizor can OHKO with a Choice Band-boosted Bullet Punch, although without bulk investment it is 2HKOed by Power Gem. Cobalion outruns non Scarf sets and OHKOes with Iron Head. Mega Aggron and Mega Steelix can take any attack and OHKO with Heavy Slam. Empoleon can wall Nihilego that lack Electric coverage, remove Stealth Rock with Defog, and take it down with a STAB Super Effective Scald.
**Faster Physical attackers:** If Nihilego lacks a Choice Scarf, most of the tier's faster Physical attackers can force it out or just straight up OHKO it. Mega Aerodactyl and Mega Beedrill can outrun and OHKO with Earthquake and Drill Run, respectively. Both can also severely dent it with Pursuit. Terrakion resists both of Nihilego's STABs and can OHKO with Earthquake; Close Combat also has a very good chance to OHKO. Infernape can OHKO with Earthquake, and if it carries a Life Orb or Choice Band, Close Combat will OHKO as well. Choice Band Azumarill can OHKO with a +1 priority Aqua Jet, though Sludge Wave means it can't switch in.
**Specially bulky Pokemon:** Blissey stops Nihilego dead in its tracks and can take it down with Seismic Toss. Muk-Alola comfortably walls Nihilego, and can 2HKO with Knock Off and Pursuit.