Disclaimer : Well, I'm still learning english, so sorry if there is some mistake on this :c
S Rank :
Clefable : Pretty much one of the best mon of the tier atm, the ban of gross and darm-g let him breathe. Beside, he can fit in a lot of team thanks to his great movepool, with a lot of options.
Magearna : Well, gross is gone, so that mean mag is back. Lot of options, my favourite is actually the Heart Swap, quite fun to use atm.
S- Rank :
Landorus-T : Well, Darm-G, Torna and Ash Gren are gone, so that mean that Lando is better. Not much to say, great scarf, also good breaker, a good mon overall.
Lopunny-Méga : the best méga atm on the tier, but also suffer from the 4 move syndrome, which why he is not S. When you have so much options such as Fake Out + Quick Attack, CC, U-turn, Triple Axel, and Return, you want to run all of them, but u can't unfort :/
Heatran : Unfort, not as good than before. But he still have a great typing, an excellent bulk and a great movepool. I don't really believe that he is "the best mon of the tier atm ", not for me.
A+ Rank :
Cinderace : In a tier with Z-move, and his ability Libero, he can easily break Pex, or bulky water in general, and also Kommo-O, with Psychium Z Bulk Up or Electrium Z Work Up. His only issue is that he can only bring four move, unfort again :/
Toxapex : Quite a good mon atm, but also quite passive, unfort, and there is a lot of way to break into him. Don't deserve a S rank for me.
Kartana : A great mon, quite good at snowballing, and also a quite underated check at Dvish. nothing more to say.
Gliscor : Also a excellent mon, good speed tier, good breaker, can completely use pex as a fooder. Nothing more to say
Aegislash : Hit hard with specs, can be a pain with Sub toxic, and he's an excellent pick in HO with air balloon and SD. Nothing more to say, except that he is quite slow, unfort :/
Kyurem : The sub roost set is sooooo great, capable of dealing with a lot of stuff. Freeze dry help him a lot, thanks to that he can easily beat pex. Only regret, his typing :/
Zapdos : A Rilla, lop, kart and lando check, and also one of the best defog on the tier. Nothing much to say.
Hydreigon : You can see here that this VR is very personal. Hydreigon is not the same mon than before for me, since the tier lost Ash-Gren, and I was using him with bulky spread to break/check ash-gren. He's still a nice Heatran SI, but I personnaly think that he doesn't worth an S or S- Rank, because atm my spread are completely useless now :c and atm there's better Z-move User
A Rank :
Alakazam : Sash Counter is sooo nice on HO, when NP LO is awesone to break. Nothing more to say again :)
Dragapult : Great Speed tier, good as nuking defensive core with a Z, as also a quite nice bulk. Only issue, quite easy to RK, and have trouble to deal with steel without a Z or Fire Blast, unfort :/
Excadrill : a quite good mon, Sand Rush is bread and butter ^^
Tyranitar Mega :He is back, better than ever in this tier. Good at checking a lot of stuff. Excellent rock setter and also good for trapp psy type/tias/tios.
Hippowdon : quite good at checking Cinderace. A nice rock setter, and also great in tandem with Excadrill. as again, nothing much to say :)
Slowbro : such an excellent wall, capable of dealing with most physical attacker on the tier. The mega as the capability of being a deadly late game sweeper, while the normal is just a momentum machine.
Scizor Mega : another great mon, but he lose an utility by checking Mgross. Still good and deadly at late game, but not as before.
Garchomp : Great SR setter and tran SI. But to me, he has some trouble in the current meta, since the well know tankchomp isn't really good atm, and the Z move is a bit outclassed by other users, since mons like Corviknight/skarm are bad in the current meta. But it's chomp, so A rank
Latios Mega : Still good on the meta, it's pretty self explanatory.
Tangrowth : the ban of torna and darm give him breathe. The Physical def is still awesome, while I don't really see the interest of a AV set when AshGren is ban, but perhaps it may be good.
Ferrothorn : Not as good than before, it's also pretty self explanatory.
Charizard Mega X : Still really MU reliant, which make quite hard to rank, but he's still an excellent breaker overall, and an excellent sweeper also.
Reuniclus : One of the best Toxa abuser, also a great mon overall, except for speed. An excellent underated pick ^^
Mandibuzz : an excellent answer to DD pult, Excadrill, Aegi... it's actually another nice underated pick.
Chansey/Blissey : agree with Lameflame, one of them should be on a VR
Melmetal : well, there's no gross here. So he can destroy everything with Double Iron Bash. Quite fun to use atm.
Volcarona : Having the boots doesn't save him and doesn't make him broken. He still have issue with which move I chose on my last slot, which is why he drop here.
Tapu Fini : Well, not as good than before. But still dope to break pass fat bulky core with taunt + NM.
Rotom Heat : the same, still good at pivoting but not as before
B+ Rank :
Dracovish : Well, even if people say that this mon isn't broken, and even if he's not as dangerous compared to GEN 8 OU, you still need an SI to this no brain mon. But he's limited by his speed. So he doesn't worth an A.
Latias Mega : Well, the CM set is actually excellent, but he need a lot of preparation and he's also really MU dependant, when the support set is a support set :/. Doesn't worth an A
Rillaboom : Well, better than Bulu, grassy Slide + U-turn help him a lot. excellent when pairing with Pex. But he doesn't really hit so hard, and there's Scizor and Zapdos and Corvi on this tier. So he need some help.
Serperior : Love the scarf on HO, nothing more to say
Mew : well, mew is mew. Nothing more to say
Gengar : well, this is Alakazam in less good, because of the talent and the speed tier :/
Victini : Love to much the scarf, I can't really be objective on that, unfort :)
Mawile Mega : Well, no gross around. So Maw is back on the game ^^
B Rank :
Chansey/Blissey : the other is here, I just don't know yet which one :/
Tapu Lele : Not as good than before, even with Mgross ban. still fun to use, but... well, he doesn't hit so hard.
Amoonguss : Quite interesting, but, well, it's amoonguss :/
Bisharp : an excellent pick for HO. But he lack some speed :/
Gastrodon : Quite passive, but still a nice pick paired with M Scizor.
Venusaur Mega : Well, still a good mega, and a good underated pick but... with the current meta, Slowbro is better as a physical defensive tank :/
Weavile : Still a good pick with Cband and also a good trapper, but he's so frail, unfort
Rotom Wash : Well, not as good than before, and outclassed by is heat form, but still a nice pick
Medicham-Mega : Still hit hard, and Torna's ban is just good for him, but still slow and need supp to work.
Charizard Mega Y : Scorching sand add is actually nice to him. But there's still pex. and he's still having trouble to break him, even if he can burn him more easily now.
Swamper Mega : Well, rain have lose two pillar, Torna and Ash Gren, soooo....
Pelipper : Same
Manaphy : Same
Grimmsnarl : Well, he's not as good than mew, but still an excellent screen supp ^^
Jirachi : not as good than he was. unfort :/
Gyarados : The two are nice, and I put them on the same level. The mega is still good, but the normal have Moxie + Z, which help him a lot to snowball. The Mega have in counterpart an better bulk overall and a nice typing.
Tapu Koko : well, koko isn't the mon that he was before, since he doesn't really hit so hard. But maybe the DLC will make him shine, as a CB set could be awesome ^^
Urshifu-water : Not as good than the dark, but still an unrated pick. Still wall by pex, unfort, but have an excellent moveset and Surging Strike is an excellent move.
Tyranitar : Choice Band and AV are still here ^^
Skarmory : I stop to count how many time I said that, but........ not as good than before :c
Hoopa H : I love this mon, but his speed tier is shit :/
Terrakion : another underated pick. The ash-gren ban is actually quite good to him ^^
PS : I flex in peace with Sub Salac set :3
Kommo-O : Well, the offensive set are... well, bad, and defensivelly he can check Cinderace without a Z-Psy. so, here he is
C+ Rank :
Blacephalon : well, we all know that he can't be insane with stuff like Ttar on this tier. Quite frail, but can be insane to unprepared team.
Keldeo : Not the mon that he was before, unfort :sob:
Volcanion : a good typing, good stat, and.... that's all. Still an excellent Scizor, Rona and in a way an heatran check, but have a quite bad SpD and Speed, unfort :/
Mimikyu : Doesn't hit really hard without an SD and the LO, and his talent has been nerfed. But, with some preparation, he can succed at sweeping.
Gallade Mega : never try this mon unfort, but well, He doesn't seems to have success on the current meta, so here he is.
Suicune : Can't really be objective here, I love so much this mon... but in actual NatDex OU, he's not good. He really need a lot of supp to sweep.
Alomomola : Well, not darm-g anymore. So, not as good than before. And he wasn't so good before
Garchomp Mega : Hit hard, nice bulk, nice typing, but terrible speed :/
C Rank :
Heracross Mega : Well... Hit hard but still slow, and doesn't have any priority like MMaw :/
Houndoom-Mega : Still an interesting pick to build around, and on sun he just hit stupidely hard after an NP. But well, he's a fire type, and there's Pex/Chansey :/
Pinsir-Mega : Well, he can't were the HDB, sooo... :/
Nidoking : One of my favourite mon, shit why is he so slow :c
Mamoswine : Need a lot of supp to break. But still good at.
Aggron-Mega : I try him once, and he wasn't so good as I expected.
Ribombee : Sticky are not so good atm, but he's the best setter, especially when Torna/ash-gren/MGross are gone ^^
Torkoal : same than Bombee, sun are not the best pick atm
C- Rank :
Thundurus-Therian : well, he's slow, and he lack a Fly Stab.
Dracozolt : Vish in less good. Can miss and there's more immunity to Bolt Beak than Fishious Rend
Hawlucha : Lucha, well... when Clefable is one of the best mon of the tier :/
Venusaur : Sun are not good atm :/
Marowak Alola : Can be good with Poltergeist, never try but I heard about him
Muk Alola : An excellent alternative to Tyranitar, since he can easily trapp Tias/tios and Lele, and he's also a good check to Zam, he have a pretty nice tipping but... the super berries have been nerfed, and his other ability are not that good.
Buzzwole : When Urshifu Dark was here, He was on almost all my team. Now, well, even with torna gone, he still need a ton of supp :/
Xurkitree : Can be good with Z-Hypnosis, but... his speed tier is bad, unfort.