Nightmares
There has been ongoing discussion in the community about Darkrai and its place in the metagame. With recent innovation for Darkrai at an all time high, with new techs such as Ice Beam Red Orb and Diancite Thunder, Darkrai has already cemented itself as one of the top threats in the metagame. However, the point at which prep for Darkrai has come is quite great in quantity and yet Darkrai is still finding ways to smash teams. As such, I believe the best course of action for the current metagame is to
suspect Darkrai.
I'll put forward some ban and anti-ban countermeasures for the rest of the playerbase to interpret:
Issue 1: Lack of diversity in checks
Here is the main issue I have with Darkrai, and I'm fairly certain everyone has this problem as well. Darkrai, within its three sets, has no counters (it actually has Blue Orb variants of both capable of countering it, but they aren't too reliable switchins and are fairly easy to wear down). The sheer existence of Red Orb is capable of removing most of the offensive problems Darkrai has, albeit in the exchange of giving Darkrai a new set of checks - particularly mons like Primal Groudon and Entei. However, remove Red Orb from the fray, and Darkrai appears to have innocently lost its capability of muscling through the metagame. However, the issue with this is that there are only two reliable counters to Darkrai: Magearna and Buzzwole. This allows for Darkrai's team to adapt heavily to these counters, and it's already being seen with Magearna being targeted with certain techs, such as Nature's Madness Tapu Lele, Lunala, other Magearna, Noivern - the options that a Darkrai team has to pressure through Magearna is large enough so that it is incapable of lasting too long. Buzzwole is also highly exploitable - and unfortunately, is very capable of being lured by targets like Pinsirite Kartana, yet again giving Darkrai the lead. What this then comes to is the situation of revenge killers - particularly -atespeeders and faster Fighting-types like Terrakion. Unfortunately for them, the existence of the Diancite set completely invalidates most counterplay that doesn't involve -atespeed - and what makes it worse is that Diancite effectively has a free slot to experiment with - so you could find yourself lured by one and be unable to answer it due to its massive speed.
Issue 2: Initial power
Blastoisinite Darkrai has a few key features that pull it away from other breakers alike despite its only decent speed - its high initial power allows it to force out a lot of Pokemon that would otherwise be able to 1v1 them - such as support Arceus. This very high initial power from Dark Pulse on the Blastoisinite set effectively means it can drop coverage for Substitute, making it a really tough Pokemon to play around, and potentially allows it to fodder Pokemon like Blissey that would attempt to soft-check it. Substitute on Blastoisinite is also capable of forcing Focus Blast Magearna to potentially miss, which can mean game over for some Cameruptite variants. What also makes Substitute so good is its capability to allow Darkrai to fish for flinches if need be - due to Dark Pulse's high power, a flinch can often be game ending for certain Pokemon (i.e Sablenite Magearna), and if Substitute stays in tact, it can often bust the side strategy.
Issue 3: Coverage
Red Orb and Diancite sets are capable of utilizing coverage that can potentially lure their checks quite easily. For example, Focus Blast, Ice Beam, Thunder, and Sludge Bomb are all viable coverage moves and can be slotted into Diancite Darkrai to be able to deal with some of its best checks. Red Orb Darkrai is also capable of slotting Ice Beam and Sludge Bomb in its final coverage slot, capable of luring certain half-checks such as Entei and Zygarde, which when used over Thunderbolt can provide devastating results against some teams.
However, I do not believe Darkrai is entirely unhealthy for the metagame, and there are a lot of things that I enjoy about its presence that help me enjoy the current state of MnM (with the exception of Magearna being about, of course)
Benefit 1: Anti-ghost countermeasure
Darkrai fucks Ghosts and Psychics very hard. Pokemon such as Manectite Mew and Lunala have dropped off in usage thanks to Darkrai being able to punish them heavily. Arceus-Ghost also disappeared off of the face of the earth because of Darkrai, and a bunch of other weak pivots have been slowly moving away from the meta due to the threat of Darkrai. A viable Dark-type finally means these mons, supported by Magearna are finally less able to properly operate, and this therefore means that strong defensive backbones are heavily weakened by it, making for a more proactive experience with the metagame, and arguably a more skillful one.
Benefit 2: Promotes proactive counterplay
As continued with the point above, Darkrai is very good for promoting proactive counterplay and opening ways of checking Pokemon previously thought difficult to beat (i.e Magearna, Landorus-Therian). Pokemon that are usually extremely heavily threatened by it are capable of utilizing pivoting moves or doubles to avoid its presence entirely, and it's this quality that can make some teams quite brutal that would be able to work even better when Darkrai wasn't present.
Here are some possible anti-ban arguments for Darkrai that I follow. I believe I am on the line for now, but this has been from experience within the past 24 hours, not overall experience.
Downfall 1: -atespeed and Magearna
Darkrai is unfortunately plagued by these issues above. -atespeed can cause major issues for Darkrai, stopping it from pulling off an immediate sweep, and Magearna, or realistically any variant with Fleur Cannon is capable of forcing out Darkrai multiple times, making it extremely susceptible to wear even from the Pokemon it comes in easily on. Not only this, but Magearna is an incredible force to be reckoned with defensively - very few Pokemon are capable of answering it with ease, especially when its set is unrevealed. This can sometimes make Darkrai a burden for teams that wish to proactively check Magearna due to a lack of checks.
Downfall 2: Adaptation of checks (i.e Sablenite Buzzwole)
Certain Pokemon have adapted to reliably check Darkrai. For example, Sablenite Buzzwole, mainly utilized by user
In The Hills is a fairly strong Darkrai check that doesn't fall to the same issues that Magearna does when fighting Darkrai. Certain -atespeed users have also adapted to make Darkrai's capability of breaking much harder, particularly bulky Altarianite Zygarde, which is a fairly reliable answer to both sets despite its weakness to Sludge Bomb and lack of reliable recovery. Altarianite Landorus has also come into relevance as an emergency check to Darkrai as one of its side attributes along with its general difficulty to be handled. And if recovery is desired, Hippowdon and Gliscor are viable alternatives that have been used to a good efficiency. As such, Darkrai has a good range of reliable punishes, and I find this is one thing that stops it from being completely broken.
Downfall 3: Offensive pressure
Unfortunately for Darkrai, its presence has caused a rise of bulky offense teams designed to never let certain strong threats such as Magearna, Primal Kyogre and itself in. Most Pokemon on bulky offense and hyper offense are capable of avoiding the OHKO from Blastoisinite Darkrai's Dark Pulse, and many other Pokemon are capable of revenge killing it that aren't always -atespeed users, such as Pinsirite Zeraora, and the aforementioned Terrakion, another huge threat of this current metagame. Unfortunately, some of these can be highly exploited by Diancite, and this is what makes Darkrai a massive threat even despite offensive counterplay.
Overall, I believe it is time to judge this nightmare of a Pokemon and send it to suspect. Some of my reasoning is outright lacking for my points against it, and I feel as if that may be enough to make me signal a ban for this Pokemon.
(I'd also like a suspect of Magearna some time in the near future thanks!)