Gengar

When taking a close look at what it has in its arsenal, Gengar has quite a number of reasons to bear that menacing grin on its face. A unique Ghost / Poison typing on top of the ability Levitate gives Gengar some handy immunities to Normal-, Fighting-, and Ground-type moves as well as some useful resistances to Fairy-, Grass-, Bug-, and Poison-type moves, allowing it to check Pokemon such as Landorus-T, Breloom, and Azumarill. However, despite these useful resistances, Gengar is somewhat held back by its poor bulk, which can make switching in even on some resisted hits challenging. Gengar makes up for this, though, boasting a notable offensive presence between its incredible base 110 Speed, high Special Attack, and superb movepool that allows Gengar to dispatch a wide range of checks. All of this comes on top of having access to a Mega Evolution that grants Gengar the ability Shadow Tag, a major improvement to its Special Attack and Speed stats, and a slight increase to its bulk that makes Gengar truly a force to be reckoned with in the Battle Spot Singles metagame.