Weavile

Weavile's excellent Speed tier gives it access to the fastest Fake Out in the metagame and the ability to remove the foes' items with Knock Off before they can act. This is particularly useful against Pokemon such as Power Herb Xerneas and most Sitrus Berry users such as Dialga and Palkia; however, unless Weavile uses Knock Off as Xerneas switches in, Xerneas can just use Moonblast immediately, OHKOing Weavile if its Focus Sash has been broken or activating it if it is still intact. Weavile's typing and STAB combination allow it to deal with threats such as Mega Salamence and Rayquaza easily, greatly damaging them with Icicle Crash even after an Attack drop from Intimidate and OHKOing Salamence if it decides not to Mega Evolve. Although Weavile's typing isn't horrible offensively, it doesn't grant it a significant defensive presence; furthermore, Weavile's bulk is extremely low, leaving it vulnerable even to resisted Ghost-, Ice-, and Dark-type attacks and to most priority attacks, such as Fake Out and Sucker Punch. Weavile is also susceptible to priority status moves such as Thunder Wave from Prankster Thundurus, as losing its Speed advantage often makes Weavile useless. Lastly, even though its STAB combination isn't resisted by many Pokemon, if Weavile can't hit the foe super effectively, it struggles to deal with bulky Pokemon, especially Primal Groudon and Primal Kyogre.