I didn't do a complete indepth use of every mon to get a good idea of where everything should fit on the VR, but I got most of them, and I might take a break from mons, so I'll post this list now.
S
These are the best mons in the tier. They’re mandatory and do more for a team than anything else.
Tentacruel
No explanation needed.
Hypno
I’m going to be controversial and put Hypno and Tentacruel into the same subrank. I think Hypno is inferior to Tent and that there is a margin between them, but not enough to put Tent into a new sub rank than Hypno. Hypno provides invaluable defensive help and helps check monsters like Dugtrio and Kangaskhan. Having a healthy Hypno in the back, always means that you have a defensive pivot and can threaten whatever, with the exception of a sleeper, opposing Hypno and Kadabra. Hypno provides invaluable positioning and is beaten only by Tent, because of Wrap. I can see an argument for Tent to S+, because Tent’s speed does stop some mons from being viable, but the more I play, the less I see that as a strong enough argument.
A+
These are the other best mons in the tier that are worse enough to be a rank below S. They’re not as mandatory as the S ranks, but they certainly are close and every team needs to account for them.
Kadabra
I think Kadabra is the third best mon in the tier. It’s got a lot of offensive power and utility with T Wave, but it also has a lot of defensive utility by walling Hypno and other Kadabra. Taking a paralysis and being able to sit on Hypno, is huge. With Tent and Hypno healthy and Kadabra paralyzed or poisoned, you have a solid defensive core that can really form the backbone for Dragonite balanced teams.
Dugtrio
Despite Dugtrio being the best late game sweeper in the game and one of the best mid-game offensive threats, I’m putting right behind Kadabra, because of Dug’s lack of bulk and diversity compared to Kadabra.
Dragonite
Dragonite barely finishes off the A+ rank thanks to AgiliWrap. Without Wrap or Agility, Dragonite can still be a fearsome foe to face. However, AgiliWrap puts it over the top, as it’s a mon that can just win games after coming in against a sleeping mon.
A
These are really strong mons, some of the best in the tier, but don’t live up to the strength of the A+ due to some weakness. They’re not staples like the ranks above, but are really close. You don’t have to account for them as much as the above mons, but they’re something to keep in mind.
Kangaskhan
Kang is a monster and is the best wall breaker in the game. I’m putting it in A, instead of A+, because it lacks Special, and can’t deal with Wrap well. I can see an argument for A+, but I’m putting it at the top of A, personally.
Persian
The second best fast physical attacker. Slash and H Beam do a ton of damage and TBolt and BB are actually good support. Having to give up a slot for Toxic does hurt it, but not too much. Persian can sweep in the late game, support in the mid game and even can be scary in the early game. Definitely one of the best mons in the game.
Gyarados
Gyarados is arguably the best tank, or at least on of the best tanks. It’s got good defense, a good typing, good stats and a good movepool. The weakness to TBolt sucks and being slower than Kang do really stop it from being a total monster, but Gyara definitely falls just a little shy of some other mons, putting it at the bottom of A.
A-
Not quite as good as the other A ranks due to a lack of a couple of things, these mons are still solid and great additions to the tier. These mons are definitely great and don’t rely on some sort of niche, but just can’t be strong enough to kick it with the other A mons.
Vaporeon
A great defensive pivot and working as a “second tent” (at least defensively), Vaporeon is a great mon. It’s low speed and reliance on B Slam to hurt Tent does get in the way, but Vap is definitely a top mon in UU and is a great choice for balanced teams who are worried about Blizzard.
Articuno
Great Special and STAB Blizzard are a great combo. Articuno is a powerful mon that can set-up Agility and wreck in the late-game. This is a mon that I wish I had more experience with, but I have enough playing with and against it to say that it belongs in the A ranks. However, it’s reliance on Blizzard and DE for attacks, does mean that it can’t get over bulky waters without some luck and is just a little too weak to join the upper subranks of A. I’d say it’s the worst of the A mons, but still an A mon nevertheless.
B+
EB0LA said that all you need are A rank mons. You don’t need anything else to win. I don’t disagree with that per say, but I do think that B+ mons are ones that could win you a game just as well, but may be a little more specialized. Due to weaknesses, they’re not quite as universal as the A rank mons, but B+ are still fearsome and game winning mons that are basically psuedo-A ranked mons.
Dodrio
This is the most fearsome sweeper if left unchecked. Drill Peck + Hyper Beam can sweep teams on it’s own. Agility means that it doesn’t get outsped and can shake of paralysis. The only things stopping it are Rock-types and fragility. Without a Rock-type, I think a Dodrio going on a crit crusade is much scarier than Dug, imo. Dodrio is probably the most scary mon against an unprepared or poorly played team.
Tangela
I remember a year or two ago, I was suggesting we put Tangela from D to C on the VR, and now here I am suggesting it up to B+, only behind Dodrio. This little plant has certainly grown on me. Being the most definitive counter to Dugtrio and Electrics, while also sporting dual powder, growth and bind, Tangela really shines as a way to balance off offense, who otherwise might be weak to those two mons. I actually find that Tangela has enough to really hold it’s own on a team and not just feel like a glue or defensive pivot.
Electabuzz
I’m a little confused on why some other players are talking down on Buzz so much. STAB Thunderbolt is great and that Speed Tier is amazing. T Wave gives it utility and really Body Slam, Psychic, and S Toss prevent Buzz from being useless against anything. Albeit you are relying on 30% secondary effects, but it’s not as bad as what people say, at least in my opinion. Buzz can replace Kadabra with success and can function as a lead and a mid/late-game mon. I don’t see how Buzz can’t get some serious credit for things.
B
The B ranks are good mons that serve a purpose that goes beyond gimmicky or niche, but still aren’t fitable on a lot of teams due to one reason or another. They’re generally for more specialized strategies and don’t compliment normal strats that A rank mons generally prefer. However, they’re still good and can hold their own.
Haunter
This was my favorite 6th mon at one point, taking on the ability to check Normals while also being a pseudo-electric-type and putting everything to sleep with Hypnosis. However, it’s Psychic and Ground-type weakness and weakness to paralysis and crits have made it harder and harder to use. Now I have not used Haunter as much as I would like to, and it’s on my list of mons that I would like to test more, but I have played it some, and those games really made me think less of Haunter, and putting at the top of the B subrank.
Poliwrath
I didn’t touch Poli for a while and it dropped to B- on my personal VR. However, after playing it some, I’ve found that it’s a lot better than I remember it being. Obviously it can outspeed Hypno and use Hypnosis first. Really it finds its place as it works as a Dug check, that’s also bulky enough to take Wrap. And it’s typing let’s it take it on Surf and Blizzards. It’s also got great physical defensive bulk and can take hits from any physical attacker except Dodrio. It does have a weakness to Psychic and Thunderbolt and relies on Rest for recovery, if it uses recovery at all. It also has ok attacking, but may not take advantage of it’s STAB. But it gets itself a place in the meta, and Poli needs to be respected imo.
Omastar
Omastar is one Pokemon that I haven’t used very much. I almost always go for Vap, because Rock-typing isn’t something I usually need. Omastar not checking Dug also means that I even use Poli before it. It’s ability to wall Articuno and wraps cannot be denied though. I’m not sure if it should go before or after Poli. I’m putting it after, because Poli gets Hypnosis, a better movepool and can check Dug, but I can see an argument for both sides, and would be ok putting Oma before Poli.
B-
These are the niche mons that barely fit into UU. They’re good enough to be in the tier and have their own defined niche, but it’s hard to want that niche or to find a reason to use it.
Raichu
Some of you are talking about moving Raichu to NU, and I don’t know why. Agility with BoltSurf coverage makes Raichu a good sweeper. T Wave gives it utility throughout the whole game, but really Thunderbolt + Surf is great, as long as you don’t run into Tangela. Raichu is the ultimate anti-Rock-type, which makes it great with Dodrio, but also Nite and even Articuno. Raichu is a lot more niche than Buzz, but I never think of Raichu as a lesser mon. It can still scare, weaken and even sweep a team. If nothing else it speed-ties Tent and hits things hard. I think suggesting it comes down to NU is a huge disregard to its abilities.
Golem
Honestly, this is one of the mons I wanted to test, but never got the chance. I’m going to keep it in B-, but honestly I could see the argument for it going lower and thus dropping to NU. I really think that needs to be done with testing though, and since I don’t see people use it, I don’t think we should just theorymon it down. Otherwise we end up with another Tangela situation, where after finding its place, most players are good with it being UU.
C+
Nearly as good as the B mons, C+ is just a chip below the rest and ends up being not good enough for proper UU. Should definitely be feared as much as proper UU mons though.
Venusaur
Razor Leaf is amazing and hits better than Thunderbolt, which makes Venusaur great for offensive teams. It has a strong niche in the meta, being able to sleep Hypno or Kadabra and straight up kill Dugtrio, which are usually the electric-type checks/counters. This is one I’ve really only played against, so I might be overestimating it, but in the matches I played against it, it did really well.
C
This rank is more niche, but still holds a viable strength that can be used well in a serious game. They’re not quite as good for proper UU, but they’re definitely good mons with solid niches.
Dewgong
Dewgong is a lot like Omastar. The difference is Omastars better anti-wrapping utility and Rock-typing help it out more than STAB Blizzard. Dewgong is definitely a good mon that should not be underestimated, but it’s still not good enough for proper UU.
Raticate
This is a mon that I haven’t used in a long time. Super Fang and B Slam paralysis immunity are really good for offensive teams who want to break bulky mons like Kang and Vap. Sometimes a single Super Fang is enough to open the floodgates. But Raticate is really fragile and has a lot of competition for a slot. I wish I could use this mon some more, because it’s really cool, but it’s just another one that I haven’t gotten around to.
D*
I do not have enough experience with these mons to properly say if they should go into a rank or not. I want to make it clear that just because a mon can win you a game, and no other mon works in that strat, I don’t thnk that’s enough for it to come to D. If something can be used to win games, I would put it into a theoretical E rank -full of mons that can help win games. In order to be D Rank and show up on the VR, the mon would have to be good enough to bring to a serious game and not be a pick and pray choice. Unconventional and daring, but not just hoping your strat works.
* because all these mons I haven’t used enough to say if they belong or not.
Venomoth
I have only been on the receiving end of Veno, but it can do something and shouldn’t be totally underestimated. Psychic, Dual Powder is pretty decent and can do something to a team. This is a cool mon at the bottom of the barrel, that might just be good enough to belong here.
Aerodactyl
So I was told that Aero was a decent Dug niche and spent many games trying to see if that was true (It wasn’t; it’s a poor dug check); however, EB0LA has been having some success with Aero when used with Buzz. I haven’t really gotten a chance to test out this idea But I do see EB0LA and plague like it. I do have to wonder if Aero is really doing something that something else can’t do better. For me personally, the difference between a rankable D and an unrankable E, is that D Ranks are doing something that truly feels like a niche you could bring to a serious game and not feel weakened at all going in. I haven’t seen enough evidence one way or the other to really say how I feel about Aero being D or E, but it’s where my mind is at rn.
Dragonair
Played a little bit with this. I’m not confident enough to say if it should be here, but I’ll at least humor the idea. It’s a support mon that isn’t going to uproot games like NIte, but it can be annoying and potentially dangerous, especially with the right amount of luck.
UR
Honestly, I haven’t touched these mons recently, but they’re not good enough for a proper VR ranking. I could see it for E Rank, but we don’t go that low on here for good reason.
Pinisr
Can’t really say much about this since I don’t see it or play it, I think it’s UR until it can prove itself though
Moltres
I haven’t seen this thing in a long time. It might be viable, especially on something like Toxic Wrap, but it’s just not explored enough to say one way or another imo.
Golduck
I haven’t seen this do enough to consider it rankable up to D Rank. Haven’t really touched it or played against it though.
Clefable
Haven’t touched Clef in a while, but based on previous experience and playing against it, I’d put it into the E Rank (so ur). Might need more testing and playing though. It has something, but not quite enough for me to rank it.