Good evening - after some time of investigation, the National Dex council has chosen to move on with tiering action with the tiers premier dark dreamer - Darkrai itself!
At the start of this year, Darkrai was unbanned from Ubers by a reasonably large margin, with most players believing that the tier's high power level and strong speed control were sufficient to keep it in check. Although it has seen relatively little development since then, the departure of Zamazenta, by far its best answer by virtue of bulk, speed, and typing, has left a Darkrai-shaped hole in many teams, supported by an uncomfortable 3.14 score in the tier's most recent survey and continued success in National Dex Invitational. As such, the council has deemed now, shortly before the start of the next National Dex Premier League, to be an ideal time to revisit this earlier decision and see if it truly has adjusted to the OU metagame.
Darkrai has numerous strengths that can easily be discerned at a short glance. While its Dark Pulse acts as a relatively unremarkable STAB option, the metagame struggles to produce sturdy Dark resistances, with the Dark-weak Galarian Slowking and Iron Crown being crucial special walls on most teams for their general excellence into most other threats. Additionally, even resistances can be broken past by Darkrai - Focus Blast swiftly picks off Mega Tyranitar, while Clefable is chunked heavily by Sludge Bomb. This lends Darkrai to be a naturally effective wielder of both Choice Specs and Nasty Plot sets, the former utilizing options such as Ice Beam and Trick to snipe Landorus-T and Gliscor or cripple neutral targets such as Toxapex respectively, while making its STAB more spammable through Terastallizing into a Dark-type. Meanwhile, Nasty Plot sets can opt for a Z-Move to augment their breaking power - Fightinium Z can break through Ting-Lu and even weakened Blissey, which are otherwise solid checks, while Darkinium-Z brute forces almost anything after a boost, acting as a reliable breaking tool. The fact that these sets are rather malleable makes them more difficult to deal with, as switching in Toxapex or Diancie to scout the Choice Specs set can easily lose a Pokemon to Nasty Plot, whereas keeping a high-health Pokemon in against Darkrai can be muscled through by the natural power of Choice Specs. Hence, the general dirth of reliable answers to Darkrai coupled with its ability to brute force past its checks if it wishes easily make Darkrai a potent metagame force well deserving of its suspect position.
Another key component perhaps supporting Darkrai's ban, and independent of its strength as a wallbreaker, is its propensity to introduce 'hax', or uncompetitive luck elements, to a game. Yes, its main STAB Dark Pulse does come with a nasty secondary chance to flinch which can ruin a chance to retaliate, but this pales in comparison to the most infamous method it has to steal games - Hypnosis. Armed with Hypnosis, Nasty Plot, and a Focus Sash to survive revenge killers or Psychium Z to outspeed them, Darkrai can incapacitate both offensive and defensive counterplay, however, this lies on the fate of a slightly weighted coin flip. This only makes Darkrai more difficult and unreliable to manage, as conventional methods of answering sleep, such as picking a dedicated 'sleep sacrifice' at the start of the game, can be interrupted by an 'unlucky' miss from the opponent. Hence, without specific methods such as Mega Lopunny's Fake Out or Mega Tyranitar's sand and resistances, this leaves the 'safest' means of managing Hypnosis Darkrai to exploit its lower immediate power by staying in and attempting to dodge sleep, an arguably unreliable and uncompetitive interaction which removes much of the skill present in managing a standard offensive threat.
Despite the various means Darkrai has of sending the tier into the void, the maligned mythical boasts means of counterplay preventing its chokehold on the tier. While its speed is excellent and it boasts decent 70/90/90 bulk to allow setup opportunities against most defensive Pokemon, many of the tier's excellent revenge killers, including Mega Lopunny, Tapu Koko, and Choice Scarf Tapu Lele and Urshifu-R can eliminate it, boasting naturally good matchups into it courtesy of their typing and can even stomach a Dark Pulse on switch-in in a pinch. Speaking of which, relying on Dark Pulse as its sole STAB can fall short at times, as even after Terastallizing, the Choice Specs set occasionally finds itself struggling to KO neutral targets before they retaliate or pivot into a more sturdy resistance unafraid of coverage. While Darkrai has theoretical means to break through all its checks with Nasty Plot, it can suffer from 4-moveslot syndrome, as it desires Focus Blast and Sludge Bomb for Dark-and Fairy-types, Ice Beam to threaten out Landorus-T and Gliscor, and Hypnosis to grant setup, while also needing to pick between Darkinium Z to OHKO Toxapex and Assault Vest Tornadus-T and Fightinium Z for Ting-Lu. Many Terastallization options are also tailored to matchup well against Darkrai, with Tera Fairy being a prevalent option on most defensive Pokemon for its general utility and forcing it into uncomfortable interactions where it risks falling short. Although Darkrai is undeniably a potent force, the not uncommon scenarios where it falls short of its expected value against an opponent coupled with most teams being able to prevent it from spiralling through well-timed Terastallization and offensive pressure limits it from being an objectively overwhelming force.
- Reading this is mandatory for participating in the suspect test. The voting requirements are a minimum GXE of 80 with at least 50 games played. In addition, you may play 1 less game for every 0.2 GXE you have above 80 GXE, down to a minimum of 30 games at a GXE of 84. Also, needing more than 50 games to reach 80 GXE will suffice.
- The table for this can be found below:
GXE minimum games 80 50 80.2 49 80.4 48 80.6 47 80.8 46 81 45 81.2 44 81.4 43 81.6 42 81.8 41 82 40 82.2 39 82.4 38 82.6 37 82.8 36 83 35 83.2 34 83.4 33 83.6 32 83.8 31 84 30
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This has been the suspect test I have been most conflicted on, so I decided that I may as well write my thoughts down on this thread. 
