Reversal is learned by 43 species by level, 177 by machine and 20 by egg

Effect, in PokéAPI's words

“Inflicts more damage when the user has less HP remaining, with a maximum of 200 power.”

Who learns it

180 species in all, 8 of 19 games shown

Scarlet and Violet: 140 species

Species	Method	Level
Arcanine	Level up, Machine	1
Lucario	Level up, Machine	1
Mienshao	Level up, Machine	1
Malamar	Level up, Machine	1
Mienfoo	Level up, Machine	10
Falinks	Level up, Machine	30
Crabrawler	Level up, Machine	33
Crabominable	Level up, Machine	33
Torchic	Level up, Machine	36
Meditite	Level up, Machine	39
Maschiff	Level up, Machine	39
Hitmonlee	Level up, Machine	40
Vigoroth	Level up, Machine	43
Makuhita	Level up, Machine	43
Mabosstiff	Level up, Machine	43
Blaziken	Level up, Machine	49
Combusken	Level up, Machine	50
Hariyama	Level up, Machine	50
Growlithe	Level up, Machine	52
Squawkabilly	Level up, Machine	52
Passimian	Level up, Machine	55
Riolu	Level up, Machine	56
Pikachu	Machine
Raichu	Machine
Diglett	Machine
Dugtrio	Machine
Mankey	Machine
Primeape	Machine
Poliwrath	Machine
Hitmonchan	Machine
Rhyhorn	Machine
Rhydon	Machine
Scyther	Machine
Tauros	Machine
Mewtwo	Machine
Mew	Machine
Cyndaquil	Machine, Egg
Quilava	Machine, Egg
Typhlosion	Machine, Egg
Sentret	Machine, Egg
Furret	Machine, Egg
Pichu	Machine
Yanma	Machine
Pineco	Machine
Forretress	Machine
Snubbull	Machine
Granbull	Machine
Qwilfish	Machine
Scizor	Machine
Heracross	Machine
Sneasel	Machine
Swinub	Machine
Piloswine	Machine
Delibird	Machine
Skarmory	Machine
Houndour	Machine, Egg
Houndoom	Machine
Hitmontop	Machine
Entei	Machine
Shiftry	Machine
Breloom	Machine
Slaking	Machine
Medicham	Machine
Zangoose	Machine
Seviper	Machine
Monferno	Machine
Infernape	Machine
Bastiodon	Machine
Vespiquen	Machine
Croagunk	Machine
Toxicroak	Machine
Rhyperior	Machine
Yanmega	Machine
Mamoswine	Machine
Gallade	Machine
Pignite	Machine
Emboar	Machine
Timburr	Machine
Gurdurr	Machine
Conkeldurr	Machine
Basculin	Machine
Scrafty	Machine
Axew	Machine
Fraxure	Machine
Haxorus	Machine
Beartic	Machine
Bisharp	Machine
Braviary	Machine
Cobalion	Machine
Terrakion	Machine
Virizion	Machine
Tornadus	Machine
Keldeo	Machine
Meloetta	Machine
Chesnaught	Machine
Hawlucha	Machine
Decidueye	Machine
Incineroar	Machine
Yungoos	Machine
Gumshoos	Machine
Oricorio	Machine
Komala	Machine
Jangmo-o	Machine
Hakamo-o	Machine
Kommo-o	Machine
Scorbunny	Machine
Raboot	Machine
Cinderace	Machine
Rookidee	Machine
Corvisquire	Machine
Corviknight	Machine
Cramorant	Machine
Pincurchin	Machine
Eiscue	Machine
Morpeko	Machine
Zacian	Machine
Zamazenta	Machine
Kubfu	Machine
Urshifu	Machine
Regidrago	Machine
Kleavor	Machine
Sneasler	Machine
Overqwil	Machine
Quaquaval	Machine
Spidops	Machine
Lokix	Machine
Klawf	Machine
Palafin	Machine
Flamigo	Machine
Annihilape	Machine
Kingambit	Machine
Great Tusk	Machine
Slither Wing	Machine
Iron Hands	Machine
Iron Valiant	Machine
Koraidon	Machine
Iron Leaves	Machine
Okidogi	Machine
Ogerpon	Machine
Gouging Fire	Machine

Brilliant Diamond and Shining Pearl: 30 species

Species	Method	Level
Arcanine	Level up	1
Vigoroth	Level up	1, 43
Slaking	Level up	1
Lucario	Level up	1
Torchic	Level up, Egg	36
Meditite	Level up	39
Hitmonlee	Level up	40
Sentret	Level up, Egg	42
Medicham	Level up	42
Makuhita	Level up	43
Kangaskhan	Level up	44
Taillow	Level up	45
Furret	Level up	50
Combusken	Level up	50
Hariyama	Level up	50
Growlithe	Level up	52
Blaziken	Level up	56
Riolu	Level up	56
Swellow	Level up	57
Rattata	Egg
Diglett	Egg
Mankey	Egg
Rhyhorn	Egg
Scyther	Egg
Cyndaquil	Egg
Pichu	Egg
Yanma	Egg
Houndour	Egg
Miltank	Egg
Aron	Egg

Sword and Shield: 98 species

Species	Method	Level
Arcanine	Level up, Machine	1
Lucario	Level up, Machine	1
Mienshao	Level up, Machine	1
Malamar	Level up, Machine	1
Mienfoo	Level up, Machine	10
Escavalier	Level up, Machine	24
Bouffalant	Level up, Machine	30
Buzzwole	Level up, Machine	30
Falinks	Level up, Machine	30
Wooloo	Level up, Machine	32
Torchic	Level up, Machine	36
Lillipup	Level up, Machine	36
Dubwool	Level up, Machine	38
Hitmonlee	Level up, Machine	40
Clobbopus	Level up, Machine	40
Grapploct	Level up, Machine	40
Kangaskhan	Level up, Machine	44
Herdier	Level up, Machine	48
Combusken	Level up, Machine	50
Throh	Level up, Machine	50
Sawk	Level up, Machine	50
Growlithe	Level up, Machine	52
Stoutland	Level up, Machine	54
Passimian	Level up, Machine	55
Blaziken	Level up, Machine	56
Riolu	Level up, Machine	56
Victini	Level up, Machine	56
Pikachu	Machine
Raichu	Machine
Diglett	Machine
Dugtrio	Machine
Poliwrath	Machine
Machop	Machine
Machoke	Machine
Machamp	Machine
Rhyhorn	Machine
Rhydon	Machine
Scyther	Machine
Pinsir	Machine
Tauros	Machine
Mew	Machine
Pichu	Machine
Qwilfish	Machine
Scizor	Machine
Shuckle	Machine
Heracross	Machine
Miltank	Machine
Entei	Machine
Aron	Machine
Lairon	Machine
Aggron	Machine
Vespiquen	Machine
Lopunny	Machine
Rhyperior	Machine
Gallade	Machine
Timburr	Machine
Gurdurr	Machine
Conkeldurr	Machine
Basculin	Machine
Darmanitan	Machine
Axew	Machine
Fraxure	Machine
Haxorus	Machine
Accelgor	Machine
Cobalion	Machine
Terrakion	Machine
Virizion	Machine
Keldeo	Machine
Pangoro	Machine
Honedge	Machine
Doublade	Machine
Aegislash	Machine
Hawlucha	Machine
Zygarde	Machine
Incineroar	Machine
Bewear	Machine
Silvally	Machine
Togedemaru	Machine
Jangmo-o	Machine
Hakamo-o	Machine
Kommo-o	Machine
Marshadow	Machine
Zeraora	Machine
Scorbunny	Machine
Raboot	Machine
Cinderace	Machine
Rookidee	Machine
Corvisquire	Machine
Corviknight	Machine
Cramorant	Machine
Obstagoon	Machine
Pincurchin	Machine
Eiscue	Machine
Zacian	Machine
Zamazenta	Machine
Kubfu	Machine
Urshifu	Machine
Regidrago	Machine

Ultra Sun and Ultra Moon: 44 species

Species	Method	Level
Hitmonlee	Level up	1, 61
Vigoroth	Level up	1, 43
Mienshao	Level up	1, 63
Malamar	Level up	1
Buzzwole	Level up	1
Growlithe	Level up	19
Riolu	Level up	29
Victini	Level up	33
Lillipup	Level up	33
Crabrawler	Level up	33
Crabominable	Level up	33
Herdier	Level up	38
Meditite	Level up	39
Medicham	Level up	42
Stoutland	Level up	42
Makuhita	Level up	43
Taillow	Level up	45
Throh	Level up	45
Sawk	Level up	45
Heracross	Level up	46
Bouffalant	Level up	46
Passimian	Level up	46
Escavalier	Level up	49
Kangaskhan	Level up	50
Hariyama	Level up	50
Swellow	Level up	57
Mienfoo	Level up	57
Rattata	Egg
Diglett	Egg
Mankey	Egg
Rhyhorn	Egg
Scyther	Egg
Cyndaquil	Egg
Sentret	Egg
Pichu	Egg
Yanma	Egg
Houndour	Egg
Miltank	Egg
Torchic	Egg
Aron	Egg
Timburr	Egg
Axew	Egg
Togedemaru	Egg
Jangmo-o	Egg

Sun and Moon: 44 species

Species	Method	Level
Hitmonlee	Level up	1, 61
Vigoroth	Level up	1, 43
Mienshao	Level up	1, 63
Malamar	Level up	1
Buzzwole	Level up	1
Growlithe	Level up	19
Riolu	Level up	29
Victini	Level up	33
Lillipup	Level up	33
Crabrawler	Level up	33
Crabominable	Level up	33
Herdier	Level up	38
Meditite	Level up	39
Medicham	Level up	42
Stoutland	Level up	42
Makuhita	Level up	43
Taillow	Level up	45
Throh	Level up	45
Sawk	Level up	45
Heracross	Level up	46
Bouffalant	Level up	46
Passimian	Level up	46
Escavalier	Level up	49
Kangaskhan	Level up	50
Hariyama	Level up	50
Swellow	Level up	57
Mienfoo	Level up	57
Rattata	Egg
Diglett	Egg
Mankey	Egg
Rhyhorn	Egg
Scyther	Egg
Cyndaquil	Egg
Sentret	Egg
Pichu	Egg
Yanma	Egg
Houndour	Egg
Miltank	Egg
Torchic	Egg
Aron	Egg
Timburr	Egg
Axew	Egg
Togedemaru	Egg
Jangmo-o	Egg

Omega Ruby and Alpha Sapphire: 36 species

Species	Method	Level
Hitmonlee	Level up	1, 61
Vigoroth	Level up	1, 43
Mienshao	Level up	1, 63
Malamar	Level up	1
Growlithe	Level up	19
Riolu	Level up	29
Victini	Level up	33
Lillipup	Level up	33
Herdier	Level up	38
Meditite	Level up	39
Medicham	Level up	42
Stoutland	Level up	42
Makuhita	Level up	43
Heracross	Level up	46
Bouffalant	Level up	46
Escavalier	Level up	49
Kangaskhan	Level up	50
Hariyama	Level up	50
Throh	Level up	50
Sawk	Level up	50
Mienfoo	Level up	57
Rattata	Egg
Diglett	Egg
Mankey	Egg
Rhyhorn	Egg
Scyther	Egg
Cyndaquil	Egg
Sentret	Egg
Pichu	Egg
Yanma	Egg
Houndour	Egg
Miltank	Egg
Torchic	Egg
Aron	Egg
Timburr	Egg
Axew	Egg

X and Y: 36 species

Species	Method	Level
Hitmonlee	Level up	1, 61
Vigoroth	Level up	1, 55
Mienshao	Level up	1, 63
Malamar	Level up	1
Growlithe	Level up	19
Riolu	Level up	29
Victini	Level up	33
Lillipup	Level up	33
Herdier	Level up	38
Stoutland	Level up	42
Heracross	Level up	43
Makuhita	Level up	43
Meditite	Level up	46
Bouffalant	Level up	46
Escavalier	Level up	49
Kangaskhan	Level up	50
Throh	Level up	50
Sawk	Level up	50
Medicham	Level up	55
Hariyama	Level up	57
Mienfoo	Level up	57
Rattata	Egg
Diglett	Egg
Mankey	Egg
Rhyhorn	Egg
Scyther	Egg
Cyndaquil	Egg
Sentret	Egg
Pichu	Egg
Yanma	Egg
Houndour	Egg
Miltank	Egg
Torchic	Egg
Aron	Egg
Timburr	Egg
Axew	Egg

Black 2 and White 2: 34 species

Species	Method	Level
Growlithe	Level up	19
Riolu	Level up	29
Victini	Level up	33
Lillipup	Level up	33
Herdier	Level up	38
Stoutland	Level up	42
Heracross	Level up	43
Makuhita	Level up	43
Meditite	Level up	46
Bouffalant	Level up	46
Escavalier	Level up	49
Throh	Level up	53
Sawk	Level up	53
Kangaskhan	Level up	55
Vigoroth	Level up	55
Medicham	Level up	55
Hariyama	Level up	57
Mienfoo	Level up	57
Hitmonlee	Level up	61
Mienshao	Level up	63
Rattata	Egg
Diglett	Egg
Mankey	Egg
Rhyhorn	Egg
Scyther	Egg
Cyndaquil	Egg
Sentret	Egg
Pichu	Egg
Yanma	Egg
Houndour	Egg
Miltank	Egg
Torchic	Egg
Timburr	Egg
Axew	Egg