Jirachi

Jirachi is arguably the best Pokemon in DPP OU. Jirachi's fantastic typing, great movepool, and excellent stats give it limitless versatility. Jirachi is the fastest defensive Steel-type; it has the bulk, Speed, recovery, and resistances such as a crucial one to Dragon and an immunity to Toxic to fulfill almost any defensive role. However, the main source of Jirachi's prowess in DPP OU is STAB Iron Head and its 60% flinch chance due to Serene Grace. Chaining Iron Head flinches can slowly wear down even bulky foes in conjunction with sand and Knock Off while passively healing Jirachi with Leftovers. Combine this with many ways to paralyze the foe such as Body Slam, Thunder, and Thunder Wave to facilitate paraflinching, and Jirachi becomes one of the central threats in the tier all teams must be aware of.

Physical Jirachi can run a dizzying amount of viable EV spreads to take advantage of this, from focusing on HP and Speed as a fantastic utility Pokemon with options such as Stealth Rock and Substitute, fully investing in its defenses to be perhaps the best general wall in the tier with Wish and Protect, or being a great cleaner or Choice Scarf user with Attack and Speed investment and options such as Fire Punch, Ice Punch, U-turn, and Trick. Serene Grace also helps with coverage moves, as Jirachi has passive opportunities to get devastating burns and freezes from Fire Punch and Ice Punch that can bail it out of tough situations.

Jirachi also is one of the best special and mixed threats in the tier with access to Calm Mind and its great special movepool. Jirachi can customize its coverage and utility moves to handle most threats in the tier: Thunderbolt, Grass Knot, Hidden Power Ground, Psychic, and Hidden Power Fire are all options to take on foes such as Skarmory, Swampert, Hippowdon, Heatran, Magnezone, Gengar, and Scizor that can cause problems for physical Jirachi. Even with Calm Mind or an otherwise fully special moveset, Jirachi can use Iron Head to create free turns, 2HKO Tyranitar, and 4HKO specially defensive Clefable. Jirachi can also lean into its support movepool with options such as Wish, Refresh, and Substitute or even different items like Shuca Berry, Lum Berry, and Occa Berry to make its Calm Mind sets more devastating.

Jirachi has an enormous influence on the DPP OU metagame, such as being one of the best switch-ins to Choice Specs Latias while also handling all three major Dragon Dance Pokemon in Dragonite, Gyarados, and Tyranitar with a simple Wish + Protect set. Jirachi is almost singled-handedly responsible for making bulkier threats resistant to Steel such as Heatran, Swampert, and Metagross more often use Leftovers, as without it, Jirachi can eventually beat them with Iron Head and its coverage moves. Jirachi can even stop Magnezone trying to trap it by either OHKOing it with Hidden Power Ground, outdamaging it with Fire Punch, or PP stalling it out of Thunderbolt with Wish and Protect. Jirachi is also a potent stallbreaker with Iron Head, as, if Skarmory or other bulky Steel-resistant foes are incapacitated with a burn or KOed, few Pokemon on defensive teams enjoy taking it on with entry hazards up.

Jirachi primarily fears two things: strong attackers such as Heatran and Swampert that can break through its defenses and status if it isn't running Refresh. Physical Jirachi sets struggle to beat bulky Steel-resistant foes that have Leftovers, such as Heatran, Swampert, Suicune, Magnezone, Zapdos, Bronzong, Metagross, and Empoleon. Bulky Steel-types such as Heatran, Empoleon, Magnezone, Bronzong, and Metagross are particularly effective against Jirachi, as their bulk allows them to potentially outheal Iron Head with Leftovers, while Zapdos and Suicune are especially dangerous due Pressure depleting Iron Head PP. Gyarados, Swampert, and Hippowdon all can take multiple hits from physical Jirachi and hit it hard in return. Ghost-types are also annoying to Jirachi, as it can't paralyze them if it has Body Slam. Both Gengar and Rotom-A can burn Jirachi; Gengar also naturally outspeeds it, and Rotom-A is resistant to Iron Head and very bulky. Special Jirachi struggles with Roar Latias, Blissey, Tyranitar, and Encore Clefable, as it doesn't have the proper coverage or power to break through them, especially if it doesn't have Iron Head. Without Refresh or Heal Bell support, Jirachi is ruined by status. Paralysis from foes such as Magnezone, Azelf, or opposing Jirachi both makes it hard to cause other Pokemon to flinch and potentially prevents it from using Wish, while burn completely ruins its ability to do damage and slowly wears it down. While defensive Jirachi is really bulky, it can be broken down by very strong attacks such as Breloom's Focus Punch and mixed Dragonite's Fire Blast, especially with Spikes support. Jirachi can theoretically deal with all of these threats with its huge movepool and versatile stats; however, it is limited to four moveslots and can't handle everything.