Slaking

Slaking’s obscene power enables it to deal with some of 1v1’s bulkiest threats like non-Will-O-Wisp Mega Charizard X, Kommo-o, Primarina, and Tapu Fini. It also has a great movepool with coverage against other common metagame threats including Zygarde, Heatran, and Genesect and can utilize alternative spreads to beat bulkier Pokemon like Mega Gyarados. However, Slaking’s awful ability in Truant leaves it open every other turn, which is taken advantage of by Protect or Substitute users and Pokemon that are able to survive Slaking's first hit and have the means to KO it back like Aegislash and Mega Gyarados. It also faces competition from Pokemon like Diggersby, which swaps bulk and greater power on Giga Impact for a more powerful Earthquake and a better ability.