Tyranitar is likely the most necessary Pokémon on Rock-type teams because its ability raises the whole team's special defence by 1.5 times.
Tyranitar @ Choice Band
Ability: Sand Stream
EVs: 252 Atk / 4 SpD / 252 Spe
Adamant Nature
- Crunch
- Stone Edge
- Earthquake
- Fire Punch
Next, you'll need a Choice Scarf user to revenge kill boosted opponents.
Terrakion @ Choice Scarf
Ability: Justified
EVs: 252 Atk / 4 Def / 252 Spe
Jolly Nature
- Close Combat
- Stone Edge
- Earthquake
- Poison Jab
You'll next need a non-Choice sweeper that can outspeed and sweep through multiple opponents without needing to switch.
Nihilego @ Power Herb
Ability: Beast Boost
EVs: 80 HP / 176 SpA / 252 Spe
Timid Nature
- Sludge Wave
- Meteor Beam
- Thunderbolt
- Grass Knot
Sticky Web support lets Tyranitar outspeed more stuff.
Shuckle @ Mental Herb
Ability: Sturdy
EVs: 252 HP / 4 Def / 252 SpD
Calm Nature
- Stealth Rock
- Sticky Web
- Knock Off
- Encore
Source
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