So, I was thinking of making this some time, so... yeah.
For me:
Normal: Eevee (HM: Lillipup line, Glameow line, and Litleo line)
Fire: Volcarona (HM: Flareon, Fennekin, Vulpix line, Litleo line)
Water: Vaporeon (HM: Oshawott line, Keldeo)
Grass: Leafeon (HM: Cottonee line, Petelil line, Budew line, Virizion)
Electric: Shinx (HM: Jolteon, Pachirisu, Joltik line)
Ice: Glaceon (HM: Froslass, Vanillite line, Kyurem, Alolan Vulpix line)
Psychic: Espeon (HM: Gallade)
Dragon: Goomy (HM: Kyurem)
Dark: Umbreon (HM: Zorua line, Purrloin line)
Fairy: Xerneas (HM: Mimikyu, Alolan Ninetales)
Fighting: Gallade (HM: Swords of Justice, Riolu line)
Ground: Excadrill or something in Sandile line I guess?
Rock: Rockruff (HM: Lycanroc Midday)
Bug: Volcarona (HM: Scizor, Genesect, Yanmega, Ribombee)
Ghost: Mimikyu (HM: Froslass)
Poison: Roserade
Flying: Yanmega
Steel: Lucario (HM: Cobalion)