Heracross

Thanks to its monstrous Attack stat backed by two high Base Power STAB attacks, Mega Heracross is one of the most threatening wallbreakers in the tier. Its wallbreaking power is further enhanced by excellent and powerful coverage options in Rock Blast and Bullet Seed. Though Mega Heracross should primarily be used for its immense power and coverage, it also possesses great bulk and a few useful resistances. These traits give Mega Heracross a decent amount of staying power against slower builds in particular. However, Mega Heracross's bulk only goes so far, especially when one considers its mediocre Speed and four common weaknesses. Likewise, Mega Heracross is rather easy to revenge kill, especially for more offensively oriented teams. Furthermore, checks such as Tornadus-T, Landorus-T, and Talonflame are as common as ever, meaning that Mega Heracross sometimes struggles in the current metagame. That being said, Mega Heracross is great at taking advantage of some prominent Pokemon such as Bisharp, Tyranitar, and Mega Lopunny, making it an excellent choice if one is looking for a bulky wallbreaker with insane power.