Hydreigon

Hydreigon is a decently powerful wallbreaker in the tier due to a solid Special Attack stat, a good STAB move in Dark Pulse, and great coverage options like Flash Cannon and Earth Power. Despite being a primarily offensive Pokemon, decent bulk, reliable recovery in Roost, and a unique typing allow it to check a number of Pokemon such as Heatran, Ash-Greninja before transformation, Reuniclus, and Blacephalon. Hydreigon's Speed tier, while good enough to outspeed Pokemon like Tapu Lele and Kyurem-B, unfortunately narrowly misses out on base 100s. Hydreigon is also aided by its useful ability Levitate, granting it an immunity to Spikes and Toxic Spikes, meaning it doesn't have to use Roost as much as other Pokemon and making it a more reliable switch-in to Pokemon that pair well with these entry hazards such as Reuniclus. However, Hydreigon lacks the immediate power and Speed of other offensive wallbreakers and pivots in the tier like Ash-Greninja and Mega Latios. Additionally, it can be hard to justify the use of Hydreigon on a lot of teams because of how specific its niche in the tier is.