I think Hydreigon should rise to B-. He is an excellent wallbreaker in this metagame, despite its not-so-high speed stat. He has a wide movepool and great attacking stats. Despite him gaining a quad-weakness to Fairy, do remember Steel-types lost their resistances to Dark. He is also outclassed a bit by Kyurem-B and Mega Garchomp thanks to their much higher attacking stats and bulk. However, he can do the following things which allow it in my eyes to be on par with Pokemon such as Victini and Weavile:
- usually outspeeds Mega Zard X since most of them run Adamant and OHKO with Draco Meteor
- can OHKO Mega Mawile with Fire Blast (252 SpA Life Orb Hydreigon Fire Blast vs. 252 HP / 4 SpD Mega Mawile: 317-374 (104.2 - 123%) -- guaranteed OHKO)
- beats Thundurus/Landorus 1-on-1 since it can live a LO Hidden Power Ice
- resists Sucker Punch and can act as an effective Bisharp check thanks to its decent bulk
- easily threatens Tyranitar with Superpower
- eliminates Excadrill with Fire Blast
- unlike Lati@s, it has no problems disposing of Ferrothorn and some Mandibuzz
- OHKOes Heatran with Earthquake, another problem for the two Latis
- is a great switch-in to Rotom-W
- outspeeds Kyurem-B and Mamoswine and can live an Ice Shard from the latter
- threatens Skarmory, Mega Heracross, Amoonguss, Quagsire, Zapdos, Mew, Mega Manectric and Slowbro
- can 2HKO Landorus-T, Chansey and most Fairy-types on the switch
- and last, but not least, has access to U-turn to scout for Fairies and switch to the appropriate counter, such as Heatran.
Disagree with Keldeo for S, it relies too much on Choice Specs, has some annoying counters in the form of Mega Venusaur, Amoonguss and Latias which it struggles to get past and can't do that much against bird spam and hyperoffense. Keldeo is a bitch to handle if it's used in rain teams, though. Keep it A+
- usually outspeeds Mega Zard X since most of them run Adamant and OHKO with Draco Meteor
- can OHKO Mega Mawile with Fire Blast (252 SpA Life Orb Hydreigon Fire Blast vs. 252 HP / 4 SpD Mega Mawile: 317-374 (104.2 - 123%) -- guaranteed OHKO)
- beats Thundurus/Landorus 1-on-1 since it can live a LO Hidden Power Ice
- resists Sucker Punch and can act as an effective Bisharp check thanks to its decent bulk
- easily threatens Tyranitar with Superpower
- eliminates Excadrill with Fire Blast
- unlike Lati@s, it has no problems disposing of Ferrothorn and some Mandibuzz
- OHKOes Heatran with Earthquake, another problem for the two Latis
- is a great switch-in to Rotom-W
- outspeeds Kyurem-B and Mamoswine and can live an Ice Shard from the latter
- threatens Skarmory, Mega Heracross, Amoonguss, Quagsire, Zapdos, Mew, Mega Manectric and Slowbro
- can 2HKO Landorus-T, Chansey and most Fairy-types on the switch
- and last, but not least, has access to U-turn to scout for Fairies and switch to the appropriate counter, such as Heatran.
Disagree with Keldeo for S, it relies too much on Choice Specs, has some annoying counters in the form of Mega Venusaur, Amoonguss and Latias which it struggles to get past and can't do that much against bird spam and hyperoffense. Keldeo is a bitch to handle if it's used in rain teams, though. Keep it A+