BO Tier List:

S Rank:
Altaria-Mega
Hydreigon
Krookodile
Latias
Scizor

A+ Rank:
Aerodactyl-Mega
Primarina
Terrakion

A Rank:
Celebi
Doublade
Infernape
Manectric-Mega
Rotom-Heat
Slowbro
Togekiss

A- Rank:
Amoonguss
Bisharp
Mamoswine
Nihilego
Steelix-Mega


B+ Rank:
Aggron-Mega
Cobalion
Diancie
Empoleon
Gligar
Hippowdon
Klefki
Kyurem
Moltres
Slowbro-Mega
Suicune
Tsareena
Volcanion

B Rank:
Alomomola
Bewear
Blastoise-Mega
Florges
Lucario
Mienshao
Roserade
Rhyperior
Starmie
Swampert
Sylveon
Tentacruel

B- Rank:
Azelf
Bronzong
Crawdaunt
Feraligatr
Heracross
Jellicent
Muk-Alola
Nidoking
Nidoqueen
Zeraora

C+ Rank:
Barbaracle
Chandelure
Haxorus
Mantine
Reuniclus
Rotom-C
Salazzle
Sceptile-Mega
Seismitoad
Snorlax
Stakataka
Toxicroak

C Rank:
Araquanid
Chesnaught
Cofagrigus
Crobat
Linoone
Magneton
Necrozma
Palossand
Pidgeot-Mega
Shaymin
Talonflame
Tornadus
Umbreon
Zygarde-10%

C- Rank:
Absol-Mega
Articuno
Aurorus
Beedrill-Mega
Decidueye
Hoopa
Mandibuzz
Pyukumuku
Quagsire
Sandslash-Alola
Silvally-Steel
Xatu

Sewage Rank:
Blissey
Cresselia
Durant
Ferroseed
Marowak-Alola
Metagross
Porygon2
Registeel
Venomoth