Okay I would like to talk about some Pokemon that aren't listed. Because i really think there are more viable Pokemon.
Mew: It has solid stats and a very good movepool. It's not used that often, but it deserves a place in this ranking. I would say B rank is okay for it.
Aerodactyl: It has a great speed, i think just Deo outspeeds it and with CB it can hit hard. Thanks to Ability Rock Head it doesn't lose any HP from Double-Edge. I would rank it in B+.
Slaking: Some people say it isnt viable. I say a CB Return in your face is viable af. Slaking outspeeds with his 100 base speed a lot of stuff, even Modest Latis. Switch ins? Really rare. Even a 0- SpAtk Fire Blast is a 1HKO on Forretress. It has also Shadow Ball to catch the possible Gengar switch-in. Return is a 1HKO on a lot of things. And you can even go for Hyper Beam. You are locked for 1 turn but in late game it can be usefull. I would rank it A-
Mew: It has solid stats and a very good movepool. It's not used that often, but it deserves a place in this ranking. I would say B rank is okay for it.
Aerodactyl: It has a great speed, i think just Deo outspeeds it and with CB it can hit hard. Thanks to Ability Rock Head it doesn't lose any HP from Double-Edge. I would rank it in B+.
Slaking: Some people say it isnt viable. I say a CB Return in your face is viable af. Slaking outspeeds with his 100 base speed a lot of stuff, even Modest Latis. Switch ins? Really rare. Even a 0- SpAtk Fire Blast is a 1HKO on Forretress. It has also Shadow Ball to catch the possible Gengar switch-in. Return is a 1HKO on a lot of things. And you can even go for Hyper Beam. You are locked for 1 turn but in late game it can be usefull. I would rank it A-