Onslaughtmons Viability Rankings
Recommended items bolded, niche items italicised
Not in any particular order within tiers
S Tier
S- Tier
Dondozo (Rocky Helmet, Leftovers, Heavy-Duty Boots, Ability Shield)
Gholdengo (Steelium Z, Air Balloon, Choice Scarf, Choice Specs, Covert Cloak)
Urshifu-Rapid-Strike (Choice Band, Choice Scarf, Focus Sash, Punching Glove, Protective Pads)
A Tier
A+ Tier
Alomomola (Heavy-Duty Boots, Assault Vest, Rocky Helmet)
Blaziken (Mental Herb, Leftovers)
Cyclizar (Heavy-Duty Boots)
Grimmsnarl (Light Clay)
Gliscor (Toxic Orb)
Clodsire (Black Sludge, Heavy-Duty Boots)
Terapagos (Heavy-Duty Boots, Leftovers)
A Tier
Tapu Koko (Choice Specs, Terrain Extender)
Tapu Lele (Choice Specs, Choice Scarf, Fightinium Z, Terrain Extender)
Weezing-Galar (Heavy-Duty Boots, Black Sludge)
Zamazenta (Choice Band, Leftovers)
Kingambit (Life Orb, Black Glasses / Dread Plate, Leftovers, Choice Band)
Volcarona (Heavy-Duty Boots, Firium Z, Focus Sash, Buginium Z)
Raging Bolt (Booster Energy, Leftovers)
Ditto (Choice Scarf)
Great Tusk (Booster Energy, Rocky Helmet)
Toxapex (Black Sludge, Heavy-Duty Boots)
Melmetal (Choice Band, Punching Glove)
Kartana (Choice Scarf, Choice Band, Focus Sash, Normalium Z)
Gyarados-Mega (Gyaradosite)
Iron Valiant (Choice Specs, Booster Energy)
A- Tier
Tornadus-Therian (Heavy-Duty Boots, Assault Vest)
Kyurem (Choice Specs, Loaded Dice, Heavy-Duty Boots)
Ogerpon-Wellspring (Wellspring Mask)
Ferrothorn (Rocky Helmet, Leftovers)
Moltres (Heavy-Duty Boots)
Corviknight (Rocky Helmet, Leftovers)
Landorus-Therian (Leftovers, Rocky Helmet)
Dragonite (Loaded Dice, Heavy-Duty Boots)
Samurott-Hisui (Choice Scarf)
Sableye-Mega (Sablenite)
Zoroark-Hisui (Focus Sash, Normalium Z)
Iron Treads (Booster Energy, Rocky Helmet)
Rillaboom (Choice Band, Life Orb, Miracle Seed)
Cinderace (Heavy-Duty Boots, Leftovers)
Heatran-Mega (Heatranite)
Scizor-Mega (Scizorite)
Quagsire (Leftovers, Heavy-Duty Boots)
Delphox-Mega (Delphoxite)
Goodra-Hisui (Leftovers, Assault Vest)
B Tier
B+ Tier
Clefable (Leftovers, Heavy-Duty Boots)
Greninja-Bond (Choice Specs, Life Orb)
Diancie-Mega (Diancite)
Charizard-Mega-Y (Charizardite Y)
Slowking-Galar (Heavy-Duty Boots, Black Sludge)
Pecharunt (Black Sludge, Heavy-Duty Boots)
Zeraora-Mega (Zeraorite)
Garganacl (Leftovers, Heavy-Duty Boots)
Lokix (Life Orb, Choice Band)
Bisharp (Eviolite)
Thundurus-Therian (Focus Sash, Life Orb)
Ceruledge (Focus Sash, Weakness Policy)
Garchomp (Rocky Helmet)
Victini (Choice Band, Choice Scarf
Ting-Lu (Leftovers)
Tapu Fini (Leftovers)
Lopunny-Mega (Lopunnite)
Meowscarada (Choice Band, Choice Scarf)
Ninjask (Heavy-Duty Boots, Mental Herb, Leftovers, Focus Sash
B Tier
Weavile (Choice Band, Life Orb, Focus Sash, Heavy-Duty Boots)
Zapdos (Heavy-Duty Boots, Assault Vest)
Hatterene (Heavy-Duty Boots, Leftovers)
Heatran (Choice Scarf, Leftovers, Heavy-Duty Boots)
Butterfree (Focus Sash, Heavy-Duty Boots)
Scizor (Life Orb, Metal Coat)
Magnezone (Choice Specs, Leftovers)
Greninja-Mega (Greninjite)
Ceruledge (Focus Sash, Weakness Policy)
Haxorus (Lum Berry, Choice Band, Leftovers)
Ursaluna (Flame Orb)
Medicham-Mega (Medichamite)
Kommo-O (Kommonium Z, Throat Spray)
Manaphy (Leftovers)
Latias-Mega (Latiasite)
Garchomp-Mega (Garchompite)
Skeledirge (Heavy-Duty Boots, Leftovers)
B- Tier
Sceptile (Sitrus Berry)
Orthworm (Sitrus Berry)
Hoopa-Unbound (Life Orb)
Iron Crown (Booster Energy, Choice Specs)
Barbaracle-Mega (Barbaracite)
Mawile-Mega (Mawilite)
Banette-Mega (Banettite)
Chandelure-Mega (Chandelurite)
Xurkitree (Choice Specs, Psychium Z)
Mamoswine (Life Orb, Never-Melt Ice)
Slither Wing (Life Orb, Choice Band, Booster Energy)
Aegislash (Life Orb)
Primarina (Leftovers, Throat Spray)
Serperior (Leftovers, Miracle Seed)
Latios-Mega (Latiosite)