Unearthing the post-Zygarde Metagame

Prior to Zygarde's ban, it was a lot harder to get away with Grass-types that didn't resist Ground-type attacks. However, without Zygarde, other Ground-type checks like Rotom-W and Celesteela can be effective, so there's a lot more choice in Grass-types to pick from. Ferrothorn is now the best Grass-type that fits on teams the easiest; its typing provides it with valuable resistances to Water-, Fairy-, and Electric-type attacks, allowing it to check Pokémon like Ash-Greninja, Tapu Koko, Magearna, and Choice-locked Tapu Lele. In addition to this, it also provides Spikes support, which is very significant in a bulkier metagame. Similarly, Amoonguss also got better and has been appearing more since Zygarde's ban. Notably, it can provide useful utility between Spore, Stun Spore, and Sludge Bomb poison, meaning that it can pressure the opposition quite well. It's especially useful against Flying- and Psychic-types like Tornadus-T and Mega Alakazam. Furthermore, Amoonguss does not have to waste turns trying to heal up thanks to Regenerator, meaning that it can easily generate momentum in its favor. Unlike Ferrothorn, Amoonguss can check Pokémon like Kartana and Tapu Bulu. Lastly, there's Mega Venusaur, which has also been appearing more and more since Zygarde's ban. It can provide a lot of useful utility between its great typing and bulk, allowing it to check Pokémon like Ash-Greninja, Mega Mawile, and Tapu Koko, and similarly to Amoonguss, it can harass teams with Sludge Bomb as well as Leech Seed. While it's really similar to Amoonguss, Mega Venusaur manages to set itself apart by virtue of its higher bulk, which allows it to check Mega Mawile and Magearna more reliably, and its offensive prowess.

Celesteela and Toxapex form a classic defensive core on balance teams, beating a plethora of top-tier threats—Ash-Greninja, Magearna, Landorus-T, and Mega Alakazam, to name a few. Zygarde's departure makes the core even better, as it no longer requires a partner like Tangrowth, Clefable, or Reuniclus to deal with Zygarde, freeing up the surrounding team's composition.

Unlike other Pokémon mentioned in this article that benefit from Zygarde's departure due to their bad matchup against it, Garchomp and Gliscor benefit from the reduction in competition for them as Ground-types. That's not to say that's the only way they benefit, however—Gliscor no longer needs to run as much Speed investment, Ice Fang, and/or more Attack investment to break Zygarde's Substitutes with Earthquake. More generally, they both very much enjoy the drop in usage of Pokémon like Clefable, Tangrowth, and Curse Mega Scizor thanks to Zygarde's exit, as well as other small changes like Landorus-T running Hidden Power Ice less often.

While previously bothered by Zygarde's presence, Rotom-W no longer has to be worried about getting punished as a team's Ground check, which was what was mainly holding it back. Thanks to Zygarde's ban, Rotom-W is now one of the main Pokémon that you will commonly find on VoltTurn teams, as its Volt Switch is practically unblockable thanks to Hydro Pump pressuring the Ground-types that would stop it. Defensively, Rotom-W's Flying- and Fire-type resistance is extremely useful to switch into the omnipresent Tornadus-T and Heatran, and to add on to that, thanks to Levitate, it is a major annoyance to common Ground-types like Landorus-T, Garchomp, and Gliscor. In addition to all this, Rotom-W has also benefited from the fall of Tangrowth and rise of Ferrothorn, because it couldn't bother Tangrowth while Ferrothorn is crippled heavily by Will-O-Wisp.

During the Zygarde metagame, Tangrowth was the go-to bulky Grass-type for bulky offense and balance teams alike because of its distinguished ability to beat common Zygarde sets consistently, unlike the other common Grass-types in the tier, namely Tapu Bulu, Ferrothorn, and Amoonguss. With Zygarde gone, Tangrowth is not as ubiquitous as it once was, with numerous teams now opting for the aforementioned alternatives. This is not to say Tangrowth is not worth using anymore, however; it is still a great check to numerous metagame staples in Ash-Greninja, Landorus-T, Mega Alakazam, and Tapu Koko, but it does face more competition now.

With Zygarde's ban, Pokémon to check it are no longer needed. This was especially a big hit for Avalugg and Buzzwole, which saw niche usage partially for their ability to answer Zygarde. Neither of these Pokémon are completely useless now, as they can still check other threats to stall like Mega Mawile in the case of Avalugg, and both can also check Landorus-T, Gliscor, and Kartana. However, role compression is extremely important on stall right now, and between the very slim range of Pokémon that they check, they're often hard to justify using.

Slowbro and its Mega Evolution were quickly rising to the spotlight in OU. This was primarily for their ability to reliably check Zygarde. So, with Zygarde's ban, Slowbro naturally lost a sizable part of its niche. Fortunately for them, while they started accumulating usage, they were explored a lot more in their roles and are now still used to check some of the most prominent wallbreakers like Mega Medicham, Mega Lopunny, and Protean Greninja lacking Dark Pulse.