A- --> A
Necrozma is disgustingly versatile, and in the current UU metagame this trait is invaluable. Thanks to its phenomenal coverage, incredible set-up options, Prism Armor, and incredibly well rounded yet efficient stats offensively and defensively, Necrozma is able to be run in a myriad of ways. Of course, this seems great, though what exactly makes this so good in the current UU metagame? After all, Mew is just as versatile if not more, and it's considered a below average Pokemon in OU.
1: Actual Win-Con
Right out the gate, Necrozma has something Mew doesn't: power. Base 107/127 offenses are shockingly powerful in conjunction with Dragon Dance/Calm Mind/Autotomize variants, and with Prism Armor's utility along with its already solid defensive spread, its otherwise underwhelming defensive typing is not only remedied, but makes it so set-up is not even remotely an inconvenience. Prism Armor allows for Necrozma to live game-changing hits that allow for it to get boosts easily and efficiently even in the face of its threats. Plus, thanks to being marked as super effective, Weakness Policy is great for getting even faster set up at the cost of said item being consumable. You manage to reap the benefits of the item without needing to take a devastating blow; with a better typing and stat spread, in this regard, it vastly outclasses Rhyperior.
Some relevant example calcs:
252 Atk Drapion Knock Off (97.5 BP) vs. 0 HP / 0 Def Prism Armor Necrozma: 184-217 (54.9 - 64.7%) -- guaranteed 2HKO
+2 252+ Atk Doublade Shadow Sneak vs. 0 HP / 0 Def Prism Armor Necrozma: 190-225 (56.7 - 67.1%) -- guaranteed 2HKO
252 SpA Chandelure Shadow Ball vs. 0 HP / 4 SpD Prism Armor Necrozma: 234-276 (69.8 - 82.3%) -- guaranteed 2HKO
Additionally, unlike Rhyperior and its competition, it is pit with more powerful, flexible set up/coverage options. The new addition of Dragon Dance allows for it to play physical, and thanks to Photon Geyser's unique trait of changing how it hits the target, it doesn't need to worry about losing a reliable STAB move no matter what set you opt to run. What's even better is the coverage it can run; Earthquake, Stone Edge, Heat Wave, Flash Cannon, Dark Pulse, and Photon Geyser provide ubiquitous coverage for Necrozma with both its special and physical sets that allow for it to safely pry apart the tier defensively barring Milotic, Umbreon, and Vaporeon. Dark types that are immune to Photon Geyser such as Morpeko, Incineroar, and Drapion are similarly weak to Necrozma's Earthquake/Earth Power, for example, letting it not fear potential immunities. For resists, all relevant threats are weak to Earth Power, Dark Pulse, and Flash Cannon.
2: Psychic STAB's importance
Much unlike in OU, Psychic STAB is much, much stronger in UU. When one of the best defensive Pokemon in the tier is Weezing-Galar, and when Poison and Fighting types as a whole are so common, Psychic STAB becomes incredibly useful to have. This powerful STAB typing and a phenomenal move in Photon Geyser to capitalize upon it with turns what's otherwise a barrier from preventing a sweep into less to eliminate prior to set up. What's also important to note is that
Necrozma, aside from Gardevoir, is the only relevant Psychic type in the tier that has speed that is able to set up for a sweep. Despite its overall competition as a Psychic type, this particular niche is incredibly valuable. Unlike Gardevoir, it has a generally easier time setting up due to its lack of an additional Poison and Steel weakness with Prism Armor and its solid defensive stats. In conjunction with its flexibility as a sweeper, Necrozma plays a role unlike anything else in the tier.
3: Defensive Utility
Something else that gives Necrozma an edge over its offensive competition is its defensive utility. Not only does Prism Armor allot it easier set up, but this allows for it to better survive opposing attacks as a whole, allowing for its utility to become much more of a noteworthy attribute. Its access to Stealth Rock, Toxic, recovery, Dual Screens, Thunder Wave, and Trick Room allows for it to play more roles than just the conventional sweeper. Even better is its ability to check what would otherwise wall its offensive variants thanks to Toxic. On top of this, access to Morning Sun and Moonlight in conjunction with keeping its incredible STAB base 127 Special Attack Photon Geyser keeps it an active threat in the battle all the same. Its main competition in this department is Reuniclus, which not only has Magic Guard but also has more reliable recovery in Recover to remain consistently healthy and an easier switch-in. While this is a detriment to this niche, access to Stealth Rock, a better speed tier, and Prism Armor gives it a niche over Reuniclus, as well as an unpredictable edge.
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So, overall, we know Necrozma for sure is a good Pokemon; its solid A- tier reflects this. Why does any of this mean it's warranted a higher tier? After all, it is walled by a lot of the tier's most common Pokemon, and it wears down much quicker in comparison to its competition. This is very true; Necrozma is probably not going to get any higher than A unless we see a fallout or tier rise of Milotic, Vaporeon, Umbreon, and similar defensive threats; it's also true that each of its sets have an Achilles Heel of some sort and cover every base; and it's true that it suffers hard from 4MSS. However, this is not why I believe Necrozma deserves to be a tier higher. I believe the biggest reason to its rise comes in its
versatility.
The tier, as we know, is incredibly mixed in its contents. There are so many different things to account for; different defensive Pokemon, new offensive threats, and powerful utilitarian Pokemon. However, something to bear in mind is that many of these Pokemon tend to be relatively standard. What I mean is that what you see is often what you get; if you see a Milotic or a Weezing, you may see deviations, but you know they're going to be walling you. However, Necrozma is much different; not only is it a menace offensively, but it is extremely dangerous defensively as well. Unlike most of anything else in the tier, it has an extremely powerful ability in being a splashable, flexible Pokemon that can play to your team's needs. If you need a strong cleaner that breaks Weezing, Necrozma is perfect; if you need a rocker that breaks Weezing, Necrozma is also perfect; if you need a Trick Room setter that can set rocks and spread status, Necrozma is perfect. The ability to fit whatever role you need in a tier full of efficient yet relatively standardized Pokemon along with having the stats, typing, coverage, and utility to properly fulfill said roles in the tier provides it with a niche unlike any other, even among its competition. It can cripple what would wall its offensive variants, break what would handle its utility sets, and will be stunningly consistent all the same.
Overall, tl;dr--I believe Necrozma is warranted a rise for its fantastic, consistent versatility; its ability to act as a potent win con; its great utility and longevity as a utilitarian; and, lastly, its relevant typing, stat spread, and ability.
Other noms:
Togedemaru rise: I actually do agree with this. I've seen it a couple times on the ladder now, and without Magnezone/Magneton around, its typing is unique right now with Toxtricity and co. running around, giving it a pretty effective niche as a utility mon and a pivot. I don't know if B- is about right for what I think of it, but I would say C+, personally.
Noivern rise: 100% agreed. Similar to Necrozma, it is incredibly versatile, and even more consistent than Necrozma at what it does and what it is capable of doing. Along with its great (yet somehow unique atm) typing and stat spread, I don't at all see why it isn't considered S tier.
Reuniclus drop: Agreed, but not 100%. While I still think this thing is fantastic, I believe its speed tier and middling defenses are becoming much larger of an issue now that we have things like Incineroar and Toxtricity running around. I think its best set down the line will probably be AV since it'll allow for it to check Toxtricity and Sun spam more effectively, but we'll have to see. It's still pretty flexible, which, as I've said many times, is a pretty powerful trait in UU. Super good mon, though, and I wouldn't be against keeping it in A+ whatsoever.
Araquanid rise: Agreed. Its typing is phenomenal, as is its stat spread to check many of the offensive threats in the tier. Plus, with Toxtricity now a thing, webs are extremely good right now. I can see arguments stating otherwise given how the tier's power level just kicked up a notch, but its typing has gotten surprisingly good with what's ultimately dropped.