Gen 8 Doubles OU
Metagross @ Shuca Berry
Ability: Clear Body
EVs: 248 HP / 172 Atk / 40 Def / 48 Spe
Adamant Nature
- Steel Roller
- Ice Punch
- Stomping Tantrum
- Meteor Mash
Terrain support is needed for this set. Steel Roller is an incredibly strong STAB that has the side effect of removing the terrain on the field. This move only works when a terrain is active. Fortunately, Rillaboom and Tapu Fini are both very common and really good in this meta, and can easily be paired with Metagross, activating terrain and allowing Metagross to use Steel Roller and deal a huge amount of damage (Rillaboom and/or Tapu Fini can just switch back in later to activate terrain again). Ice Punch and Stomping Tantrum are coverage. The former deletes both Landorus forms and does a ton of damage to Zygarde, while the latter decimates Heatran and dents Incineroar. Meteor Mash is a secondary steel STAB move that can be used outside of terrain. (Metagross can't fit Protect into it's moveset sadly)
Clear Body makes Metagross immune to the ever-present Intimidate and prevents it's speed from getting dropped by moves like Icy Wind (unless it's coming from Kyurem-B). Shuca Berry helps Metagross survive ground moves such as Zygarde's Thousand Arrows/Waves and Landorus-I's Earth Power. 172 attack EVs and an Adamant nature allows Metagross to always OHKO bulky Kyurem-B with Steel Roller. With 48 speed EVs and Tailwind support, it outspeeds Naganadel, the best Tailwind setter for offensive teams. The rest of the EVs are in HP and defence.
Some good partners:
The two best terrain setters in the meta. Rillaboom's Grassy terrain gives Metagross passive recovery and also further weakens Earthquakes, while Tapu Fini's Misty Terrain blocks status such as Amoonguss' Spore. If either of these terrains are active, Metagross can use Steel Roller to deal a lot of damage. These 'mons can be swapped back in later to set their terrain back up and allowing Metagross to use Steel Roller again. (Indeedee-F and Tapu Lele can also work, but aren't as good)
A great Tailwind setter for bulkier teams. Metagross really appreciates the Tailwind support, since it can outspeed 'mons like Naganadel, Heatran, and Landorus-I with Tailwind up. Zapdos can safely bring Metagross is with Volt Switch after setting Tailwind. Metagross also deals with Kyurem-B and Diancie, two 'mons Zapdos struggles against.