Hello there!
Having found BIGJRA’s resource immensely useful during my Pokemon Reborn monotype runs, I was looking for something similar for this game. The man himself made a version some 5-6 years ago, which is now obviously outdated, and I couldn’t find anything more recent. So I took it upon myself to compile a guide myself. After unguided monoice and monofighting playthroughs (and lots of time looking through the route encounters on the wiki) I think I’ve achieved something fairly accurate. It goes up to the Pokémon League as of now, so Pokemon relegated to the post-game, like some Deltas and most Legendaries, aren’t included. If you notice any errors, please do not hesitate to make a comment and I will correct it!
Thanks to BIGJRA for inspiration and for formatting, which I am shamelessly copying 
Updated to version 1.2.7
This is a list that shows what different Pokemon are available at any given time in game in a monotype run.
Each spoiler represents one section of the game, separated by certain level-capped fights on Hard difficulty. They include the most readily available member of the evolution line of the Pokemon, and do not mention Pokemon available in previous areas—though many evolved Pokemon can be found in the wild at later stages, allowing simpler acquisition, this guide’s sole focus is on when a Pokemon is first available. In cases where two evolutions of the same family become available simultaneously, the earliest evolution will be listed. Pokemon that first become available in the Friend Safari will be listed once more when they are able to be encountered elsewhere. The guide may not be completely accurate if playing with Purity Mode enabled.
Eevee is listed once more when it becomes available to players who did not choose it as a starter.
- Italics indicate Pokemon that will evolve into a given type.
- Underline indicates Pokemon that will lose that type by their final evolution (mainly for collecting).
Strikethroughindicates Pokemon which will have a mega-evolution that changes into the target type, such as Sceptile → Dragon. Whether or not these are legal for your monotype run prior to obtaining the appropriate mega stone, or at all, is up to you.- An asterisk* indicates Pokemon available earlier than the given section via Friend Safari.
All types that do not feature any new Pokemon will be listed at the bottom of each spoiler.
Starters
Dark: D. Squirtle, Eevee
Dragon: D. Charmander
Electric: Eevee
Fairy: D. Bulbasaur, Eevee
Fighting: D. Squirtle
Fire: Eevee
Ghost: D. Charmander
Grass: Eevee
Ice: Eevee
Normal: Eevee
Psychic: D. Bulbasaur, Eevee
Water: Eevee
Nothing new: Bug, Flying, Ground, Poison, Steel, Rock
Beginning to Trainer School (Midna Town)
Bug: Caterpie, Durant, Dwebble, Shuckle, Weedle
Dark: Poochyena, Purrloin, Stunky
Electric: Blitzle, Elekid, Pikachu, Rotom
Fairy: Blitzle, Carbink
Fire: Heatmor, Onix, Ponyta, Rotom
Flying: Caterpie, Hoppip, Rotom, Woobat, Zubat
Ghost: Cubone, Gastly, Rotom
Grass: Exeggcute, Hoppip, Rotom
Ground: Baltoy, Bunnelby, Cubone, Diglett, Drilbur, Geodude, NidoranF, NidoranM, Onix, Phanpy
Ice: Rotom
Normal: Bunnelby, Patrat, Meowth
Poison: Gastly, NidoranF, NidoranM, Stunky, Weedle, Zubat
Psychic: Abra, Baltoy, Exeggcute, Woobat
Rock: Carbink, Geodude, Dwebble, Nosepass, Onix, Roggenrola, Shuckle
Steel: Drilbur, Durant, Nosepass, Onix
Water: Rotom
Nothing new: Dragon, Fighting
Trainer School to Abyssal Cultist (Ancient Ruins)
Dark: Carvanha, Corphish, Magikarp
Fairy: D. Dwebble (Cake), Marill
Fighting: Tyrogue
Flying: Magikarp
Ground: Barboach, Sandshrew
Ice: Shellder
Normal: Bidoof, D. Dwebble (Cake)
Poison: Qwilfish
Psychic: Staryu
Rock: Corsola
Water: Barboach, Bidoof, Buizel, Carvanha, Clamperl, Corphish, Corsola, Finneon, Goldeen, Magikarp, Marill, Qwilfish, Remoraid, Shellder, Staryu, Totodile
Nothing new: Bug, Dragon, Electric, Fire, Ghost, Grass, Steel
Abyssal Cultist (Ancient Ruins) to Suntouched Gym
Dark: Pancham, Sableye
Dragon: Axew
Electric: Magnemite
Fighting: Machop, Makuhita, Riolu, Timburr
Flying: Natu
Ghost: Sableye
Ground: D. Grimer
Normal: Whismur
Psychic: Natu
Rock: Relicanth
Steel: Axew, Magnemite, Riolu
Water: Relicanth
Nothing new: Bug, Fairy, Fire, Grass, Ice, Poison
Suntouched Gym to Nora (Metchi Town)
Bug: Surskit
Dark: Seedot
Dragon: Charmander
Fairy: Ralts
Fighting: D. Scyther, Poliwag, Ralts, Sawk, Throh
Fire: Charmander
Flying: Charmander, Ducklett, Mantyke, Surskit
Ghost: D. Aipom
Grass: Lotad, Pansage, Petilil, Seedot, Sudowoodo
Ground: Wooper, Shellos
Ice: D. Scyther, Seel
Normal: D. Aipom
Poison: Tentacool
Psychic: Ralts
Rock: Sudowoodo
Steel: Piplup
Water: Alomomola, Basculin, Clauncher, Ducklett, Krabby, Lotad, Mantyke, Oshawott, Panpour, Piplup, Poliwag, Seel, Shellos, Surskit, Tentacool, Wooper
Nothing new: Electric
Nora (Metchi Town) to Vipik Gym
Bug: Anorith
Dragon: Skrelp, Tyrunt
Electric: D. Ralts
Fairy: Togepi
Fire: Cyndaquil, D. Sunkern, D. Wooper
Flying: Aerodactyl, Archen, Doduo, Fearow, Togepi, Wingull
Ghost: Frillish
Grass: D. Wooper, Lileep
Ground: Mudkip, Tympole
Ice: Amaura, D. Ralts
Normal: Doduo, Fearow, Furfrou, Marill (breed), Minccino
Poison: D. Sunkern, Skrelp
Rock: Aerodactyl, Amaura, Anorith, Archen, Cranidos, Kabuto, Lileep, Omanyte, Shieldon, Tirtouga, Tyrunt
Steel: Shieldon
Water: Frillish, Kabuto, Luvdisc, Mudkip, Omanyte, Skrelp, Squirtle, Tirtouga, Tympole, Wingull
Nothing new: Dark, Fighting, Psychic
Friend Safari slot 1
Bug: Burmy, Caterpie, Combee, Illumise, Karrablast, Ledyba, Paras, Scatterbug, Sewaddle, Shedinja, Spinarak, Surskit, Venonat, Volbeat, Weedle, Wurmple
Dark: Houndour, Inkay, Magikarp, Nuzleaf, Pancham, Poochyena, Purrloin, Stunky
Dragon: Seadra, Skrelp, Swablu, Tyrunt
Electric: Chinchou, Dedenne, Emolga, Helioptile, Magnemite, Minun, Pachirisu, Panpour, Plusle, Stunfisk
Fairy: Carbink, Clefairy, Dedenne, Jigglypuff, Mr. Mime, Snubbull, Spritzee, Swablu
Fighting: Mankey, Pancham, Sawk, Throh, Tyrogue
Fire: Houndour, Litleo, Magmar, Numel, Onix, Pansear, Slugma, Sunkern, Torkoal,
Flying: Burmy, Caterpie, Chatot, Combee, Drifloon, Ducklett, Emolga, Farfetch’d, Hoppip, Ledyba, Magikarp, Mantyke, Pidgey, Pidove, Scatterbug, Shedinja (breed + evolve), Spearow, Starly, Surskit, Swablu, Taillow, Wingull, Wurmple
Ghost: Drifloon, Misdreavus, Pumpkaboo, Shedinja
Grass: Burmy, Carnivine, Cherubi, Exeggcute, Foongus, Gloom, Hoppip, Lotad, Maractus, Nuzleaf, Oddish, Pansage, Paras, Petilil, Pumpkaboo, Sewaddle, Snover, Sudowoodo, Sunkern, Weepinbell
Ground: Baltoy, Bunnelby, Burmy, Graveler, Numel, Onix, Palpitoad, Sandshrew, Shedinja (breed), Stunfisk, Tympole, Wooper
Ice: Amaura, Cubchoo, Lapras, Seel, Snover, Vanillish
Normal: Bidoof, Bunnelby, Chatot, Dunsparce, Farfetch’d, Glameow, Helioptile, Herdier, Jigglypuff, Lickitung, Litleo, Meowth, Patrat, Pidgey, Pidove, Rattata, Sentret, Skitty, Spearow, Stantler, Starly, Swablu, Taillow, Teddiursa, Zigzagoon
Poison: Ekans, Foongus, Gloom, Gulpin, Oddish, Qwilfish, Skrelp, Spinarak, Stunky, Trubbish, Venonat, Weedle, Weepinbell, Wurmple
Psychic: Baltoy, Bronzor, Drowzee, Elgyem, Espurr, Exeggcute, Inkay, Lunatone, Mr. Mime, Slowpoke, Solrock, Spoink, Unown
Rock: Amaura, Boldore, Carbink, Corsola, Graveler, Lunatone, Nosepass, Onix, Slugma, Shieldon, Solrock, Sudowoodo, Tirtouga, Tyrunt
Steel: Bronzor, Burmy, Karrablast, Klang, Magnemite, Nosepass, Onix, Shieldon
Water: Alomomola, Basculin, Bidoof, Buizel, Chinchou, Clamperl, Corsola, Ducklett, Goldeen, Krabby, Lapras, Lotad, Luvdisc, Magikarp, Mantyke, Palpitoad, Psyduck, Qwilfish, Remoraid, Seadra, Seel, Skrelp, Slowpoke, Surskit, Tirtouga, Tympole, Wailmer, Wingull, Wooper
Vipik Gym to Damian (Rezzai Cavern)
Bug: Venipede, Vibrava
Dark: D. Pidgey, Krokorok, Sneasel
Dragon: D. Pidgey, Seadra, Swablu*, Vibrava
Electric: Electrike, Lanturn, Luxray
Fairy: Cottonee, Floette, Mime Jr.*, Swablu
Fire: Growlithe, Fennekin, Fletchling
Flying: Fletchling, Swablu
Ghost: Marowak
Grass: Cottonee, Roselia, Servine, Weepinbell*
Ground: Hippopotas, Krokorok, Marowak, Vibrava
Ice: Sneasel
Normal: Castform, Ditto, Dunsparce, Girafarig, Kecleon, Flecthling, Swablu
Poison: Grimer, Gulpin*, Roselia, Venipede, Weepinbell*
Psychic: Fennekin, Girafarig, Mime Jr.*, Slowpoke*
Water: Lanturn, Psyduck*, Seadra*, Slowpoke*
Nothing new: Fighting, Rock, Steel
Damian (Rezzai Cavern) to Helios Gym
Bug: Heracross, Larvesta, Pinsir, Scyther
Dark: Eevee
Dragon: Bagon, Goomy, Mareep
Electric: Eevee, Emolga*, Mareep, Minun*, Pachirisu*, Plusle*
Fairy: Chikorita, Clefairy*, Eevee, Milotic
Fighting: Heracross
Fire: Eevee, Larvesta
Flying: Bagon, Chatot*, Emolga*, Pinsir, Scyther, Starly*
Ghost: Phantump*, Pumpkaboo*, Yamask
Grass: Chikorita, Eevee, Gogoat, Phantump*, Pumpkaboo*
Ice: Eevee, Lapras*, Smoochum
Normal: Chatot*, Eevee, Gogoat, Porygon, Skitty, Smeargle, Starly*, Stoutland*
Poison: Koffing
Psychic: Chimecho, D. Lotad, Eevee, Smoochum, Solosis, Wynaut
Water: D. Lotad, Eevee, Lapras*, Milotic
Nothing new: Ground, Rock, Steel
Helios Gym to Sonata Gym
Dark: D. Budew
Dragon: Dragonair, Druddigon, Treecko
Electric: D. Koffing
Fairy: D. Budew, D. Litwick, Klefki, Slurpuff, Spritzee*
Fighting: Hawlucha, Primeape*
Fire: D. Combee, D. Litwick, Litwick, Ninetales, Slugma, Sunkern, Torkoal
Flying: D. Koffing, Dragonair, Hawlucha, Tropius
Ghost: Banette*, Dusclops, Glalie (breed + evolve), Honedge, Litwick, Mismagius
Grass: D. Munchlax, Sunkern, Treecko, Tropius
Ground: Rhyhorn
Ice: Cryogonal, Glalie, Spheal
Normal: Chansey, Kangaskhan, Raticate*, Snorlax
Rock: Lairon, Rhyhorn, Slugma
Steel: D. Combee, Honedge, Klefki, Lairon
Water: Spheal, Wailmer*
Nothing new: Bug, Poison, Psychic
Sonata Gym to Kepler Gym
Bug: D. Dunsparce
Dark: D. Clamperl
Dragon: D. Clamperl
Fairy: D. Clamperl
Fighting: Chespin
Grass: Chespin, Maractus*, Turtwig
Ground: Turtwig
Psychic: Beldum
Steel: Beldum
Water: D. Dunsparce
Nothing new: Electric, Fire, Flying, Ghost, Ice, Normal, Poison, Rock
Kepler Gym to Selene Gym
Bug: Ariados*, Drapion (breed), Joltik, Vivillon, Yanmega
Dark: Absol, Cacturne, Deino, Drapion, Froakie, Honchkrow, Pupitar, Scraggy
Dragon: Deino, Noivern
Electric: Eelektross, Joltik
Fairy: Audino, D. Liepard, Mawile
Fighting: Chimchar, Mienfoo, Scraggy
Fire: Camerupt*, Chimchar, Darmanitan, Magmar*, Simisear*
Flying: Delibird, Honchkrow, Noivern, Sigilyph, Vivillon, Yanmega
Ghost: D. Liepard, Golurk
Grass: Bulbasaur, Cacturne, D. Noibat, D. Scraggy, Tangrowth
Ground: Camerupt*, Golurk, Pupitar
Ice: Delibird
Normal: Audino, Miltank, Spinda, Vigoroth
Poison: Ariados*, Bulbasaur, D. Shinx, Drapion
Psychic: Sigilyph
Rock: Pupitar
Steel: D. Noibat, D. Shinx, Klink*, Mawile
Water: Froakie
Friend Safari slot 2
Bug: Anorith, Durant, Dwebble, Heracross, Joltik, Pineco, Shelmet, Shuckle, Swadloon, Vibrava, Whirlipede, Yanma
Dark: Cacnea, Corphish, Gothorita, Frogadier, Krokorok, Murkrow, Pawniard, Sableye, Scraggy, Spiritomb, Zorua
Dragon: Charmeleon, Druddigon, Grovyle, Fraxure, Noibat, Sliggoo, Vibrava
Electric: Electrike, Joltik, Luxio, Magneton, Pikachu, Voltorb
Fairy: Audino, Bayleef, Cottonee, Kirlia, Swirlix, Sylveon, Togetic
Fighting: Buneary, Combusken, Hawlucha, Heracross, Kirlia, Machoke, Makuhita, Mienfoo, Monferno, Pignite, Poliwhirl, Scraggy, Quilladin
Fire: Braixen, Charmeleon, Combusken, Monferno, Pignite, Quilava
Flying: Charmeleon, Delibird, Doduo, Golbat, Hawlucha, Hoothoot, Murkrow, Natu, Noibat, Skarmory, Togetic, Tropius, Woobat, Yanma
Ghost: Cubone, Golett, Phantump, Sableye, Shuppet, Snorunt, Spiritomb, Yamask
Grass: Bayleef, Cacnea, Cottonee, Ferroseed, Grotle, Grovyle, Ivysaur, Lileep, Phantump, Quilladin, Roselia, Servine, Swadloon, Tropius
Ground: Barboach, Cubone, Diglett, Golett, Grotle, Hippopotas, Krokorok, Marshtomp, Nidorina, Nidorino, Phanpy, Rhydon, Vibrava
Ice: Bergmite, Cryogonal, Delibird, Jynx, Snorunt
Normal: Aipom, Audino, Bouffalant, Buneary, Chansey, Doduo, Furfrou, Girafarig, Hoothoot, Loudred, Miltank, Minccino, Porygon, Smeargle, Sylveon (breed), Vigoroth
Poison: Golbat, Ivysaur, Nidorina, Nidorino, Roselia, Seviper, Whirlipede
Psychic: Braixen, Chimecho, Girafarig, Gothorita, Jynx, Kirlia, Munna, Natu, Woobat, Wynaut
Rock: Anorith, Binacle, Cranidos, Dwebble, Kabuto, Lileep, Omanyte, Rhydon, Shuckle
Steel: Durant, Ferroseed, Fraxure, Magneton, Pawniard, Pineco, Prinplup, Skarmory
Water: Barboach, Binacle, Corphish, Croconaw, Dewott, Frogadier, Kabuto, Marshtomp, Omanyte, Poliwhirl, Prinplup, Wartortle
Selene Gym to Amphitrite Gym
Bug: Accelgor*, Dustox*, Escavalier*, Ninjask, Parasect*, Shedinja
Dragon: D. Bergmite, Gible
Electric: D. Cyndaquil, Thundurus
Fairy: Granbull*
Fighting: D. Shuckle
Fire: D. Snorunt
Flying: Dustox* (breed + evolve), Ninjask, Thundurus
Ghost: D. Snorunt, D. Solosis, Shedinja
Grass: Bellossom, Parasect*, Sawsbuck
Ground: Gible
Normal: Linoone, Sawsbuck, Stantler*, Zangoose
Poison: Bellossom (breed), Dustox*
Psychic: D. Geodude, Grumpig* , Hypno*
Rock: Barbaracle*, D. Bergmite, D. Geodude, D. Snorunt, D. Solosis
Steel: D. Cyndaquil, D. Shuckle, Escavalier*
Water: Barbaracle*
Nothing new: Dark, Ice
Amphitrite Gym to Erebus Gym
Bug: D. Metang, Ledian*
Dark: Malamar*
Dragon: D. Growlithe
Electric: Heliolisk*
Fairy: D. Misdreavus
Fighting: Emboar*, Torchic*
Fire: D. Chinchou, Emboar*, Torchic*
Flying: Ledian*
Ghost: D. Chinchou
Grass: Abomasnow*
Ground: D. Metang, Mamoswine
Ice: Abomasnow*, Avalugg, Beartic*, D. Misdreavus, Mamoswine, Vanilluxe*
Normal: D. Growlithe, Furret, Heliolisk*, Lickitung
Poison: D. Girafarig, D. Heatmor, D. Yamask
Psychic: Bronzong*, D. Doduo, Malamar*, Musharna*
Steel: Bronzong*, D. Girafarig, D. Heatmor, D. Yamask
Nothing new: Rock, Water
Friend Safari slot 3
Bug: Larvesta, Pinsir, Scizor, Scyther, Skorupi
Dark: Carvanha, Skorupi, Sneasel, Vullaby, Zweilous
Dragon: Dragonair, Flaaffy, Gabite, Shelgon, Zweilous
Electric: Blitzle, Eelektrik, Electabuzz, Flaaffy, Jolteon
Fairy: Blitzle, Feebas, Floette, Klefki, Marill, Mawile
Fighting: Croagunk, Gurdurr, Meditite, Riolu, Shroomish
Fire: Darumaka, Fletchinder, Growlithe, Lampent, Larvesta, Ninetales
Flying: Aerodactyl, Archen, Dragonair, Fletchinder, Gligar, Pinsir, Rufflet, Scizor (breed), Scyther, Sigilyph, Shelgon, Vullaby
Ghost: Doublade, Dusclops, Frillish, Haunter, Lampent
Grass: Deerling, Gogoat, Leafeon, Shroomish, Tangela
Ground: Drilbur, Gabite, Gligar, Nidoking, Nidoqueen, Piloswine, Pupitar
Ice: Piloswine, Sealeo, Sneasel, Shellder
Normal: Castform, Deerling, Ditto, Fletchinder (breed), Jolteon (breed), Kangaskhan, Leafeon (breed), Marill (breed), Rufflet, Spinda, Tauros, Zangoose
Poison: Croagunk, Haunter, Koffing, Muk, Nidoking, Nidoqueen, Skorupi, Tentacool
Psychic: Abra, Duosion, Meditite, Metang, Sigilyph, Staryu
Rock: Aerodactyl, Archen, Lairon, Pupitar
Steel: Doublade, Drilbur, Klefki, Lairon, Mawile, Metang, Riolu, Scizor, Scyther
Water: Carvanha, Feebas, Frillish, Marill, Sealeo, Shellder, Staryu, Tentacool
Erebus Gym to Pokemon League
Fire: D. Petilil (Water)
Water: D. Petilil (Water)
Nothing new: Bug, Dark, Dragon, Electric, Fairy, Fighting, Flying, Ghost, Grass, Ground, Ice, Normal, Poison, Psychic, Rock, Steel
Post-game
Everything else (WIP!)
i forget