Hydreigon

Hydreigon carves out a decent niche as a strong special attacker thanks to its great STAB moves and incredible coverage. Hydreigon also has some good defensive utility thanks to its decent bulk, immunity to Ground, Psychic, and Spikes, and resistance to common moves like Scald, Hydro Pump, Volt Switch, and Pursuit. Its Pursuit resistance and better coverage give it a niche over the often superior Latios, better defeating bulkier sand teams that rely on Pursuit Tyranitar to remove wallbreaking threats. However, Hydreigon is outpaced and forced out by very common offensive Pokemon like Latios, Keldeo, Alakazam, Garchomp, and Terrakion. This is made worse by Hydreigon's weaknesses to their common attacks like Draco Meteor, Focus Blast, Outrage, and Hidden Power Ice, as well as priority moves like Ice Shard and Mach Punch. It can't fit all of Dark Pulse, Focus Blast, and Roost, which means it will either lack crucial coverage or the sustainability to wallbreak throughout the game. Lacking Roost can especially hurt due to the residual damage Hydreigon takes from sand, Life Orb, and burns. Latios outclasses Hydreigon a lot of the time due to its better defensive utility in checking Pokemon like Keldeo, Thundurus-T, and Breloom, better Speed tier to outpace Pokemon like Garchomp, Terrakion, Volcarona, and Keldeo, and greater set versatility on varying team archetypes.