The Eevee General
S Rank: Reserved for Pokemon who can sweep or wall significant portions of the metagame with little support, and Pokemon who can support other Pokemon with very little opportunity cost ("free turns"). Also the home of Pokemon who can easily perform multiple roles effectively, increasing their versatility and unpredictability. If the Pokemon in this rank have any flaws, those flaws are thoroughly mitigated by their substantial strengths.
Klefki
Nidoqueen
Venomoth
A Rank: Reserved for Pokemon who can sweep or wall significant portions of the metagame, but require some support or have some flaws that prevents them from doing this consistently. Supporting Pokemon in this rank may give opponents free turns or cannot create free turns easily themselves, but can still do their job most of the time.
Abomasnow
Ferroseed
Fletchinder
Frogadier
Golbat
Quagsire
Raticate
Sableye
Vivillon
Xatu
B Rank: Reserved for Pokemon who cannot sweep through or wall significant portions of the metagame, but can properly fulfill a given offensive/defensive niche. Support Pokemon in this category have flaws that prevent them from doing their job or are setup bait for dangerous sweepers. Pokemon who are partially outclassed by a Pokemon in A or S Rank, but are otherwise very dangerous, may also fall into this category.
Ariados
Basculin
Chatot
Combusken
Gabite
Hippopotas
Krokorok
Lunatone
Mawile
Murkrow
Pikachu
Poliwrath
Qwilfish
Rotom-N
Solrock
Stantler
Vullaby
Vulpix
Weepinbell
Zweilous
C Rank: Reserved for Pokemon who can be effective given the right support, but either have crippling flaws that prevent them from consistently executing their strategy or are typically inferior to Pokemon in the above ranks.
Arbok
Ditto
Herdier
Garbodor
Girafarig
Golduck
Grotle
Malamar
Masquerain
Mightyena
Misdreavus
Slurpuff
Swanna
Tropius
Volbeat
Wartortle
Whirlipede
D Rank: Reserved for Pokemon who have a very small niche that are for the most part, overshadowed by their flaws or are almost if not completely outclassed by another pokemon in every single way.
Bibarel
Butterfree
Cherrim
Diggersby
Lumineon
Medicham
Parasect
Seaking
fuck yeah
Watchog
E rank: Reserved for Pokemon that should never be used. Ever.
Beedrill
Every Pikachu Clone
Furret
Kricketune
Natu
I probably missed some pokemon so don't be afraid to point them out as that is somewhat what these things are for. Don't flame anyone if they say something you don't agree with.
To badass for sprites