Rhyperior -> S Rank: I definitely support this; Rhyperior is easily the most metagame defining pokemon in RU, alongisde Escavalier. Like stated in previous posts, Rhyperior can take on a impressive variety of roles and functions effectively on virtually any team, thanks to his massive bulk and devastating Attack stat. Like already stated, his glaring weaknesses to Grass and Water are easily covered by teammates, and is more than made up for by his substantial ability to wall essentially every single attacker in the tier without a Grass- or Water-type attack. Thanks to Solid Rock, Rhyperior can tank almost any single 2x effective move, and hit back off of its almost unmatched base 140 Attack. One thing people haven't really mentioned much in detail is Wish support; Wish support from teammates like Alomomola and Aromatisse makes Rhyperior almost truly invincible, as long as a teammate is left to take the Grass and Water attacks aimed at him. Rhyperior definitely fits in S-Rank - the tier for things that single handedly define the RU metagame.
Shuckle -> B+ Rank: Sticky Web is honestly one of the best, although extremely underused, playstyles in RU. There's just so many things that can absolutely wreck shit with Sticky Web, including but not limited to Moltres, Hitmonlee, Yanmega, Zangoose, and Exploud. Sure, Defog and Rapid Spin exist, but those can be dealt with by spinblockers/Braviary, or simply ignored, as Shuckle, when played right, has the ability to set SW multiple times throughout the match. Speaking of Shuckle, he faces almost no competition as a Sticky Web setter, with probably only Masquerain and Leavanny as distant seconds (really distant). His bulk allows him to reliably set hazards (and can run mental herb instead of a focus sash, unlike his competition), and is not complete setup bait, thanks to Encore. Shuckle will always pull its weight through every match, and is definitely deserving of B+.
Virizion -> A- Rank: Don't get me wrong, Virizion is a great pokemon. However, A is too high of a rank for it. The departure of Venomoth was a major blow to Virizion, who was one of the most reliable counters. Furthermore, looking at the current rankings, Virizion cannot reliably set up on any of the A ranking threats, barring Rhyperior and Sharpedo (as well as most walls, like Alomomola and Gligar). The ability to safely switch into and setup on both Rhyperior and Sharpedo is a huge plus, but its debatable typing and weaker physical defense leaves it vulnerable to many of the tier's top threats, or the coverage moves they carry (Delphox, Moltres, Zoroark, Yanmega, Reuniclus, Escavalier [gets wrecked by Megahorn], Hitmonlee, Emboar, Gallade, Meloetta, Durant, and Slowking, just looking at the A rank list). However, then you might ask, why is Virizion deserving of A rank at all? Well, there's a very good reason. After setting up a Swords Dance on the previously mentioned, extremely common pokemon, many of the threats I previously mentioned are now defeated by Virizion. Now with its blistering speed and power, it outspeeds and OHKOs Delphox, Moltres, Zoroark, Yanmega, Escavalier (after SR), Himtonlee, Slowking... (pretty much everything I listed that it cannot setup on earlier). Of course most of these relies on Stone Edge, but whatever. Basically, Virizion is a monster after it sets up, the only thing preventing it from being A rank is the lack of things it can use to set up safely. Oh, and also, its prone to being revenge killed, especially by Braviary, but that's relatively easily handled by teammates.
Ludicolo -> B/B- Rank: Ludicolo is extremely deserving of a higher rank. Ludicolo is almost a mandatory member of rain teams. Its unique typing makes him quad resist Water, as well as be neutral to Electric and Grass, godsend qualities for a rain sweeper. Plus, its Grass STAB and access to Ice Beam make it one of the few rain sweepers that can reliably get past both Grass- and Water-type pokemon, a thorn in the side for rain teams. Ludicolo has the sole exclusive right to boast this quality. For example, Heliolisk, while being immune to Water and resistant to Electric, is stopped cold by Grass-types, and Kabutops, even with its wrecking ball STAB Stone Edge (especially after Swords Dance), is checked by almost anything that can take a hit and has a Grass-type coverage move. It would make sense for Ludicolo to move up to at least B- rank, seeing that it is an almost unparalleled rain sweeper.
Rotom -> C-/D Rank: Rotom, as you probably already know, is completely outclassed by Mismagius. Mismagius is essentially a faster, stronger, and bulkier (on the special side) version of Rotom with literally everything it has to offer. Mismagius has, quite literally, Rotom's entire movepool, and more. Mismagus can set up Nasty Plot, run a defensive Calm Mind set, support with Thunder Wave/Will-O-Wisp just like Rotom, and has a much greater movepool, consisting of Energy Ball, Memento, Destiny Bond, Taunt, and Dazzling Gleam. The only reason you might even consider running Rotom over Mismagius is its Electric-type STAB, with access to Volt Switch. This is enough to earn it a C- rank, but I definitely do not see a reason it should move up.
Soutland -> E Rank: With Hippo down in E-rank, I honestly do not see a reason Soutland is kept in D. Sure, you can use manual sand, but this playstyle is so outclassed to be even worth D-rank. With Hippo in D-rank, it made sense for Stoutland to be in it, but it is just completely useless without sand, and should be kept in the same ranking as Hippo.
EDIT: I forgot one:
Fletchinder -> C+ Rank: I agree with the move down for Fletchinder. Sure, priority Acrobatics is good, but its just... well, weak. I mean, fucking Zoroark lives one:
252+ Atk Fletchinder Acrobatics (110 BP) vs. 0 HP / 0 Def Zoroark: 204-241 (78.1 - 92.3%) -- guaranteed 2HKO
Don't get me wrong, I understand Fletchinder is supposed to be a revenge killer and pick off weakened threats, but without a boosting item like Life Orb or Choice Band and a weak base 73 attack stat, its just quite underwhelming. Sure, its not impossible to set up a Swords Dance, on things like Doublade and Escavalier, but even afterwards, through my own experience, its just doesn't hit hard enough to sweep, and is actually contradictory to its "pick off weakened threats" goal. This meta is not the place for it to shine, and should be moved down to C+ rank.
