Focus Blast is learned by 1 species by level and 223 by machine

Effect, in PokéAPI's words

“Has a chance to lower the target’s Special Defense by one stage.”

Who learns it

223 species in all, 3 of 12 games shown

Scarlet and Violet: 167 species

Species	Method	Level
Charmander	Machine
Charmeleon	Machine
Charizard	Machine
Blastoise	Machine
Raichu	Machine
Sandslash	Machine
Clefable	Machine
Wigglytuff	Machine
Golduck	Machine
Mankey	Machine
Primeape	Machine
Poliwrath	Machine
Graveler	Machine
Golem	Machine
Slowbro	Machine
Muk	Machine
Haunter	Machine
Gengar	Machine
Drowzee	Machine
Hypno	Machine
Hitmonlee	Machine
Hitmonchan	Machine
Rhydon	Machine
Chansey	Machine
Electabuzz	Machine
Magmar	Machine
Snorlax	Machine
Dragonite	Machine
Mewtwo	Machine
Mew	Machine
Typhlosion	Machine
Feraligatr	Machine
Furret	Machine
Ampharos	Machine
Azumarill	Machine
Politoed	Machine
Quagsire	Machine
Slowking	Machine
Granbull	Machine
Heracross	Machine
Hitmontop	Machine
Elekid	Machine
Blissey	Machine
Tyranitar	Machine
Sceptile	Machine
Combusken	Machine
Blaziken	Machine
Swampert	Machine
Ludicolo	Machine
Shiftry	Machine
Gardevoir	Machine
Breloom	Machine
Vigoroth	Machine
Slaking	Machine
Makuhita	Machine
Hariyama	Machine
Meditite	Machine
Medicham	Machine
Grumpig	Machine
Cacturne	Machine
Zangoose	Machine
Regirock	Machine
Regice	Machine
Registeel	Machine
Groudon	Machine
Rayquaza	Machine
Deoxys	Machine
Monferno	Machine
Infernape	Machine
Rampardos	Machine
Floatzel	Machine
Riolu	Machine
Lucario	Machine
Croagunk	Machine
Toxicroak	Machine
Abomasnow	Machine
Weavile	Machine
Rhyperior	Machine
Electivire	Machine
Magmortar	Machine
Gallade	Machine
Dusknoir	Machine
Dialga	Machine
Palkia	Machine
Regigigas	Machine
Darkrai	Machine
Arceus	Machine
Pignite	Machine
Emboar	Machine
Excadrill	Machine
Timburr	Machine
Gurdurr	Machine
Conkeldurr	Machine
Krookodile	Machine
Scraggy	Machine
Scrafty	Machine
Zoroark	Machine
Cinccino	Machine
Gothitelle	Machine
Reuniclus	Machine
Haxorus	Machine
Beartic	Machine
Mienfoo	Machine
Mienshao	Machine
Golett	Machine
Golurk	Machine
Bisharp	Machine
Hydreigon	Machine
Cobalion	Machine
Terrakion	Machine
Virizion	Machine
Tornadus	Machine
Thundurus	Machine
Reshiram	Machine
Zekrom	Machine
Landorus	Machine
Kyurem	Machine
Keldeo	Machine
Meloetta	Machine
Chesnaught	Machine
Delphox	Machine
Dragalge	Machine
Clawitzer	Machine
Hawlucha	Machine
Goodra	Machine
Trevenant	Machine
Noivern	Machine
Hoopa	Machine
Volcanion	Machine
Decidueye	Machine
Incineroar	Machine
Crabrawler	Machine
Crabominable	Machine
Mudsdale	Machine
Oranguru	Machine
Passimian	Machine
Jangmo-o	Machine
Hakamo-o	Machine
Kommo-o	Machine
Solgaleo	Machine
Lunala	Machine
Magearna	Machine
Rillaboom	Machine
Cinderace	Machine
Grimmsnarl	Machine
Falinks	Machine
Zacian	Machine
Zamazenta	Machine
Urshifu	Machine
Sneasler	Machine
Enamorus	Machine
Pawmot	Machine
Armarouge	Machine
Palafin	Machine
Annihilape	Machine
Kingambit	Machine
Scream Tail	Machine
Iron Hands	Machine
Iron Jugulis	Machine
Iron Thorns	Machine
Gholdengo	Machine
Iron Valiant	Machine
Koraidon	Machine
Iron Leaves	Machine
Okidogi	Machine
Munkidori	Machine
Iron Crown	Machine

Brilliant Diamond and Shining Pearl: 96 species

Species	Method	Level
Charizard	Machine
Blastoise	Machine
Raichu	Machine
Sandslash	Machine
Nidoqueen	Machine
Nidoking	Machine
Clefable	Machine
Wigglytuff	Machine
Golduck	Machine
Mankey	Machine
Primeape	Machine
Poliwrath	Machine
Alakazam	Machine
Machop	Machine
Machoke	Machine
Machamp	Machine
Golem	Machine
Slowbro	Machine
Muk	Machine
Gengar	Machine
Hypno	Machine
Marowak	Machine
Hitmonlee	Machine
Hitmonchan	Machine
Rhydon	Machine
Kangaskhan	Machine
Mr. Mime	Machine
Jynx	Machine
Electabuzz	Machine
Magmar	Machine
Pinsir	Machine
Snorlax	Machine
Dragonite	Machine
Mewtwo	Machine
Mew	Machine
Typhlosion	Machine
Feraligatr	Machine
Furret	Machine
Ledian	Machine
Ampharos	Machine
Azumarill	Machine
Politoed	Machine
Quagsire	Machine
Slowking	Machine
Granbull	Machine
Heracross	Machine
Ursaring	Machine
Hitmontop	Machine
Miltank	Machine
Blissey	Machine
Tyranitar	Machine
Sceptile	Machine
Combusken	Machine
Blaziken	Machine
Swampert	Machine
Ludicolo	Machine
Shiftry	Machine
Gardevoir	Machine
Breloom	Machine
Vigoroth	Machine
Slaking	Machine
Exploud	Machine
Makuhita	Machine
Hariyama	Machine
Mawile	Machine
Aggron	Machine
Meditite	Machine
Medicham	Machine
Grumpig	Machine
Cacturne	Machine
Zangoose	Machine
Regirock	Machine
Regice	Machine
Registeel	Machine
Groudon	Machine
Rayquaza	Machine
Monferno	Machine
Infernape	Machine
Rampardos	Machine
Floatzel	Machine
Lopunny	Machine
Riolu	Machine
Lucario	Machine
Croagunk	Machine
Toxicroak	Machine
Abomasnow	Machine
Weavile	Machine
Lickilicky	Machine
Rhyperior	Machine
Tangrowth	Machine
Electivire	Machine
Magmortar	Machine
Gallade	Machine
Dusknoir	Machine
Palkia	Machine
Regigigas	Machine

Sword and Shield: 154 species

Species	Method	Level
Yveltal	Level up, Machine	75
Charizard	Machine
Blastoise	Machine
Raichu	Machine
Sandslash	Machine
Nidoqueen	Machine
Nidoking	Machine
Clefable	Machine
Wigglytuff	Machine
Golduck	Machine
Poliwrath	Machine
Alakazam	Machine
Machop	Machine
Machoke	Machine
Machamp	Machine
Slowbro	Machine
Gengar	Machine
Marowak	Machine
Hitmonlee	Machine
Hitmonchan	Machine
Rhydon	Machine
Kangaskhan	Machine
Mr. Mime	Machine
Jynx	Machine
Electabuzz	Machine
Magmar	Machine
Pinsir	Machine
Snorlax	Machine
Dragonite	Machine
Mewtwo	Machine
Mew	Machine
Azumarill	Machine
Politoed	Machine
Quagsire	Machine
Slowking	Machine
Heracross	Machine
Hitmontop	Machine
Miltank	Machine
Blissey	Machine
Tyranitar	Machine
Sceptile	Machine
Combusken	Machine
Blaziken	Machine
Swampert	Machine
Ludicolo	Machine
Shiftry	Machine
Gardevoir	Machine
Exploud	Machine
Mawile	Machine
Aggron	Machine
Regirock	Machine
Regice	Machine
Registeel	Machine
Groudon	Machine
Rayquaza	Machine
Lopunny	Machine
Riolu	Machine
Lucario	Machine
Croagunk	Machine
Toxicroak	Machine
Abomasnow	Machine
Weavile	Machine
Lickilicky	Machine
Rhyperior	Machine
Tangrowth	Machine
Electivire	Machine
Magmortar	Machine
Gallade	Machine
Dusknoir	Machine
Palkia	Machine
Regigigas	Machine
Victini	Machine
Excadrill	Machine
Timburr	Machine
Gurdurr	Machine
Conkeldurr	Machine
Seismitoad	Machine
Throh	Machine
Sawk	Machine
Krookodile	Machine
Darmanitan	Machine
Scraggy	Machine
Scrafty	Machine
Carracosta	Machine
Archeops	Machine
Garbodor	Machine
Zoroark	Machine
Cinccino	Machine
Reuniclus	Machine
Escavalier	Machine
Haxorus	Machine
Beartic	Machine
Accelgor	Machine
Mienfoo	Machine
Mienshao	Machine
Druddigon	Machine
Golett	Machine
Golurk	Machine
Bisharp	Machine
Heatmor	Machine
Hydreigon	Machine
Cobalion	Machine
Terrakion	Machine
Virizion	Machine
Tornadus	Machine
Thundurus	Machine
Reshiram	Machine
Zekrom	Machine
Landorus	Machine
Kyurem	Machine
Keldeo	Machine
Pangoro	Machine
Barbaracle	Machine
Dragalge	Machine
Clawitzer	Machine
Heliolisk	Machine
Hawlucha	Machine
Goodra	Machine
Trevenant	Machine
Gourgeist	Machine
Noivern	Machine
Xerneas	Machine
Zygarde	Machine
Volcanion	Machine
Incineroar	Machine
Mudsdale	Machine
Stufful	Machine
Bewear	Machine
Oranguru	Machine
Passimian	Machine
Golisopod	Machine
Turtonator	Machine
Drampa	Machine
Jangmo-o	Machine
Hakamo-o	Machine
Kommo-o	Machine
Tapu Lele	Machine
Tapu Bulu	Machine
Solgaleo	Machine
Lunala	Machine
Pheromosa	Machine
Magearna	Machine
Marshadow	Machine
Zeraora	Machine
Rillaboom	Machine
Cinderace	Machine
Clobbopus	Machine
Grapploct	Machine
Grimmsnarl	Machine
Mr. Rime	Machine
Falinks	Machine
Zacian	Machine
Zamazenta	Machine
Urshifu	Machine