Update #3: Reasoning
RISES
:ss/necrozma-dusk-mane:
Necrozma-DM is the most valuable superglue in the metagame. Forego it on hyper offense, and you're jeopardizing the matchup against Zacian-C and Ditto significantly. Forego it on a balance team, and you have to dedicate multiple slots to a Stealth Rock setter and Pokemon that can check Zacian-C and Xerneas. Even with multiple slots, Necrozma-DM's entire scope of qualities between Stealth Rock setter, Knock Off / status / Zekrom check with Earthquake, Zacian-C check, Xerneas check, and soft-check to half the metagame under Dynamax can never be reproduced by any core. No matter the developments throughout the generation, Necrozma-DM has remained as close to a constant as you can get due to these positives.
It is true that bulky Necrozma-DM comes with a fair few shortcomings. For one, it can be taken advantage of by dangerous presences such as Kyogre, Groudon, Zygarde-C, and Gothitelle. However, Necrozma-DM's ability to make progress with Stealth Rock / Knock Off / status conditions in the face of these suboptimal matchups and its otherworldly resiliency under Dynymax ensures that it hardly ever perishes without having contributed to the outcome of a match to an appreciable extent. Another drawback is Necrozma-DM's inability to properly check Assurance Zacian-C and a healthy Xerneas on its own. Nevertheless, the fact of the matter remains that Necrozma-DM is the most convenient form of counterplay to both of these threats. Besides, Zacian-C and Xerneas will both be worn down to a point where they are restricted by speed control quite easily, should they manage to outhit Necrozma-DM.
Beyond all of that, credit is to be allocated to Necrozma-DM's often overlooked Dragon Dance sets as well, being the terrific winconditions that they are. Ho-Oh's fall has been incredibly advantageous for these sets, freeing up Knock Off or Psychic Fangs over Stone Edge and thereby allowing Necroma-DM to slice through the rising Lunala and the ever-present Kyogre much more easily. Further experimentation with these sets has birthed a dangerous outcome in Life Orb variants as well, which can reach insane benchmarks such as cleanly OHKOing bulky Kyogre at +1 with Max Mindstorm and Lunala with Max Darkness.
We believe these qualities as a whole can only be conveyed properly by ranking Necrozma-DM as an S-rank presence. With this, we are removing S- as a rank.
:ss/lunala:
Lunala continues to flaunt its unique defensive perks as a hard-check to the metagame's hardest-to check threats in Groudon, Necrozma-DM, Zekrom, and Zygarde-C. This makes Lunala the ultimate countermeasure to the wide range of hyper offenses that have been popping up over the course of the past few months, and it evidently shows, letting it amass a great 60% win percentage over 20 uses in the later rounds of the winter seasonal. Lunala's ability to check Dragon Dance Necrozma-DM and Zygarde-C are especially valuable right now; with both of these setup sweepers stepping up the game by running Life Orb more frequently and being very resilient against any Choice Scarf user under Dynamax, there are little to no alternatives as far as reliable counterplay is concerned.
The shift to Eternatus + Yveltal in favor of Ho-Oh cores on pretty much every balance team is of great importance to Lunala's viability as well. Whereas Lunala fails to make much of any meaningful progress against Ho-Oh's Regenerator shenanigans, Eternatus and Yveltal are both crippled pretty harshly by Will-O-Wisp and Hypnosis. All things considered, Lunala breaks new ground by entering A for the first time.
:ss/ditto::ss/zacian::ss/darmanitan-galar:
Choice Scarf users have been at the forefront of the metagame for a long while now, but the experimentation with speed control is yet to cease.
Ditto depicts the relevance of speed control perfectly, coming in at 5th place over the last couple of rounds of the winter seasonal, outranking even Kyogre. As the safest form of speed control that punishes Calyrex-S and Zacian-C more harshly than any other option and does a good job at limiting anything from the nigh unwallable Zekrom to the metagame's most dangerous wincondition in Xerneas to even the top dog in speed tiers in Marshadow, Ditto's enormous recent success is no surprise in a metagame that has been craving for role compression desperately. It reinstates itself as a staple once again as a result.
Zacian and Galarian Darmanitan are some successful products of the aforementioned experimentation with speed control, having great outreach as revenge killers with their colorful coverage. Zacian's great Speed tier allows it to outspeed everything up to +2 Jolly Zekrom and Groudon. Intrepid Sword and Zacian's wide coverage does the rest, with Play Rough taking care of Zekrom, Zygarde-C, Xerneas, Yveltal, and Marshadow, Close Combat finishing off Zacian-C and Excadrill, Crunch OHKOing Calyrex-S, and Solar Blade denting Groudon out of commission. Galarian Darmanitan doesn't reach as much of an impressive Speed tier, but is every bit as effective when it comes to the amount of threats it can finish off, in addition to posing as a respectable, albeit prediction-reliant, wallbreaker. Both make their debut at C.
:ss/kyurem-white::ss/lapras:
Sheer Cold continues to sow the benefits of a centralized metagame, so it's natural for counterplay to rise in viability as well. Funnily enough, Sheer Cold counterplay-options happen to be Sheer Cold users themselves, solidifying their own viability indirectly.
Kyurem-W has established itself as the most reliable check to Kyogre and itself by now, and rises to A- for much of the same reasons as last time. Lapras is a cool tech that takes advantage of Kyurem-W and Sheer Cold Kyogre by firing off OHKO moves, making it a niche yet situationally potent wincondition that is capable of overcoming Sheer Cold immunities with Horn Drill and acting as a status absorber against Eternatus.
:ss/dracovish:
Dracovish has been making waves as an obscenely strong wallbreaker with the discovery of Choice Band sets alongside Thunder Wave Kyogre support to slow shared checks down and boost Fishious Rend with Drizzle. Fishious Rend reaches tremendous benchmarks under Rain, having a chance to OHKO even the likes of Eternatus and Lunala through Shadow Shield on the switch. A Speed tier that outspeeds everything up to bulky Yveltal lends Dracovish the necessary means to make use of this incredible power quite effectively though U-turn support or predictable double switches into Necrozma-DM and Yveltal. Even outside of Rain, Dracovish can easily take down Water-resistant Pokemon with its strong coverage moves; Eternatus is cleanly OHKOed by Dragon Rush after Stealth Rock damage, both Kyurem-W and Palkia are OHKOed by Dragon Rush without any necessary chip damage, and Lunala is crippled severely by Crunch. Dracovish jumps to B as a result of this lack in defined couterplay, and can only go upwards from here.
:ss/grimmsnarl:
Grimmsnarl hyper offenses are on the rise as countermeasures to the increased amounts of speed control on teams, boosting pretty much any traditional wallbreaker and setup sweeper into invincible territories. Necrozma-DM, Groudon, Zekrom, and Xerneas are notable staples on these teams, busting through counterplay and speed control alike with Grimmsnarl's support quite easily. As the catalyst of a dangerous anti-metagame trend, Grimmsnarl rises one subrank.
:ss/urshifu::ss/kyurem-black:
Speaking of wallbreakers and setup sweepers, we have two new ones making their debut in Urshifu and Kyurem-B. Similarly to Dracovish, Choice Band Urshifu doesn't know much of any effective defensive counterplay, taking advantage of the metagame's superglues in Necrozma-DM and Yveltal, cleanly 2HKOing slower Eternatus variants, and hitting everything bar the extremely niche bulky Xerneas for great amounts of damage between Wicked Blow and Close Combat. Sucker Punch and U-turn add a valuable touch of utility as well, letting Urshifu serve as a clutch revenge killer against the likes of Necrozma-DM and Calyrex-S, as well as preserving momentum in situations where it doesn't want to guess between Wicked Blow and Close Combat. Kyurem-B is a potent setup sweeper with Gothitelle support that can soft-check both Zygarde-C and Kyogre between Icicle Spear and Fusion Bolt, and act as a Sheer Cold absorber. Urshifu carves out a spot in C, whereas Kyurem-B will be modestly residing in D for now.
:ss/porygon2::ss/solgaleo:
To wrap up the rises, we have a pair of niche defensive picks finding a spot in the VR for the first time. Porygon2 does so courtesy of being a respectable check to Calyrex-S and Zygarde-C while offering Teleport support. Similarly, Solgaleo's access to Teleport allows it to form a tiny niche over Necrozma-DM. They will be ranked at C and D, respectively.
DROPS
:ss/ho-oh:
Ho-Oh has been very hard to justify for a very long while now, not really adding much of any value outside of strengthening the matchup against Spikes and Xerneas, pivoting into Choice Scarf / Choice Specs Calyrex-S and Zacian-C occasionally, and sponging some Dynamax turns from a few Pokemon at best. At worst, Ho-Oh is shut down by Eternatus and Ditto throughout an entire match and serves as bait for Kyogre, Zygarde-C, Zekrom, and Groudon. Ho-Oh doesn't convincingly check anything of note on its own, and it is this unfortunate fact that renders Ho-Oh an evident luxury in the metagame that is only really valuable for freeing up more offensive Yveltal sets on balance teams. The fact that Ho-Oh saw two uses from round 8 onwards in the winter seasonal, and won none of those matches is a pretty clear sign of its demise as well. As a result, Ho-Oh hits an all-time low by dropping to A-.
:ss/palkia::ss/reshiram:
Palkia and Reshiram have been outshadowed for ages by now. While both are still pretty respectable wallbreakers, Palkia simply doesn't cut it as a long-term wincondition between its tendency to get worn down by entry hazards, losing Leftovers to Knock Off, getting poisoned or dented by Dynamax Cannon whenever it tries to take on Eternatus, and failing to reliably break through bulky Yveltal without Rain support. Reshiram, similarly, is worn down alarmingly easily due to Stealth Rock damage and Flare Blitz plus Life Orb recoil, making it very dependant on Dynamax to put in work for extended amounts of time. Given as speed control usage is at an all-time high, this results in Reshiram being one of the easiest threats to revenge kill, making it inferior to many other setup sweepers.
:ss/giratina::ss/lugia:
Giratina and Lugia suffer under Lunala's reign as the premier physical wall. Giratina still differentiates itself as a Defogger with Pressure and thus manages to cling onto a C-ranking, but Lugia is utterly and hopelessly outclassed by Lunala in anything it may hope to accomplish other than being slightly more of an obstacle to Zacian-C.