Weavile

Weavile's great offensive stats and typing give a niche as a Pursuit trapper in DPP OU. Unlike its main competitor, Tyranitar, Weavile is really fast—fast enough that it doesn't need a Choice Scarf to outspeed frailer Dark-weak foes such as Gengar, offensive Rotom-A, Latias, and Starmie. It can instead use more versatile items such as power-boosting items including Expert Belt and Black Glasses to more easily KO them if they don't switch out or Lum Berry to absorb their status moves. Weavile also is a serviceable revenge killer; its access to a strong Ice Shard allows it to revenge kill prominent Dragon-types such as Dragonite and Flygon, and its Speed allows it to naturally outspeed +1 Tyranitar and easily OHKOes it with Low Kick. These attributes, in addition to not setting up sand like Tyranitar does, makes it particularly adept on very aggressive teams focused on frail attackers such as Infernape.

Weavile's numerous problems in the tier stem from its lack of power and atrocious survivability. Weavile does not learn strong physical Dark- and Ice-type moves and struggles to damage bulky Pokemon as a result. Ice Punch and Night Slash are simply not strong enough to KO neutral targets such as Swampert, Gyarados, and Jirachi or even very bulky walls weak to them such as Celebi and Hippowdon without a Swords Dance boost. Weavile also struggles to damage most of the Steel-types in the tier neutral to Fighting. Scizor in particular easily OHKOes Weavile with Bullet Punch and isn't hit too hard by Low Kick, Skarmory and Forretress set up with impunity, and Metagross, Bronzong, and Jirachi can survive even Choice Band or +2 Night Slash without problems and OHKO it back. All of this is exacerbated by Weavile's dreadful defensive stats, bad defensive typing, and weakness to residual damage. In most situations, Weavile is outclassed by Tyranitar as a Pursuit trapper, as while Weavile is both stronger and faster than Choice Scarf Tyranitar, it lacks the bulk and resistances to switch in easily into Latias and Rotom-A to Pursuit trap them. Scizor is also difficult competition, as its far superior bulk and defensive profile are sometimes preferable to Weavile's Speed and power. Being weak to Stealth Rock and vulnerable to status and sand means Weavile faints very quickly, as even weak special attacks like Rotom-A's Thunderbolt and Latias's Dragon Pulse easily 2HKO after Stealth Rock. Holding a Choice Band or a Life Orb makes this worse, as Weavile has to either switch out when locked on an unfavorable move or take even more residual damage to power up its weak attacks. Weavile also struggles to revenge kill Dragon Dance Dragonite with Extreme Speed, as Dragonite is faster at +1, and boosted Extreme Speed KOes it after Stealth Rock. Weavile also has issues fitting everything it wants onto one set: it needs Pursuit and often wants Low Kick and Swords Dance to help with coverage and make up for its power issues, but this leaves it wanting all of Night Slash, Ice Shard, and Ice Punch.