With Choice Scarf, Hydreigon becomes a solid revenge killer capable of beating important threats like Iron Moth, Alakazam, and Thundurus with its STAB moves while still providing utility and role compression for its team thanks to Defog and its good defensive profile against defining threats like Rotom-Wash and Aegislash. Earth Power is specifically used to revenge kill Booster Energy Iron Moth and weakened Excadrill. Fire Blast allows Hydreigon to revenge kill Excadrill and hit targets like Celesteela and Assault Vest Tangrowth hard. Hydreigon can run Defog to act as an emergency entry hazard remover, but its matchups against hazard setters like Tyranitar and Clefable make it unreliable in this role. U-turn allows it to keep momentum and bring in its teammates safely against switch-ins like Clefable, Tapu Fini, and Celesteela. Choice Scarf Hydreigon fits best on offense and bulky offense teams that appreciate a solid revenge killer against important threats that still maintains some defensive utility thanks to its typing. Speed Booster Energy Iron Boulder, Enamorus, and Choice Scarf Mienshao are some of the few Pokemon that Hydreigon outright fails to outspeed or revenge kill, making partners like Aegislash, Celesteela, and Clefable good options; Celesteela in particular enjoys Hydreigon revenge killing Iron Moth or Tyranitar with Earth Power or Focus Blast, respectively. Fairy-types like Clefable, Tapu Fini, and Mega Gardevoir can easily deal with Hydreigon and use it as setup fodder, making Steel-types like Celesteela, Aegislash, and Excadrill good partners to deal with these Pokemon. Finally, wallbreakers like Life Orb Mienshao and Choice Specs Keldeo appreciate the free entries that Hydreigon provides with U-turn by luring in Pokemon like Skarmory and Assault Vest Tangrowth These Fighting-types also enjoy Hydreigon revenge killing or forcing out faster Pokemon that may threaten them, such as Alakazam, Mega Latias, and Zeraora.

Choice Specs Hydreigon is a potent wallbreaker, being able to threaten common special walls such as Celesteela with its powerful STAB moves and coverage options. It also has more longevity and defensive utility, including a resistance to Pursuit, at the cost of Speed and more consistent STAB moves compared to other special wallbreakers like Iron Moth. Draco Meteor OHKOes threats like Iron Moth and Mega Heracross while doing significant damage to foes such as Galarian Moltres and Mega Sableye. Dark Pulse threatens Slowking and gives Hydreigon a spammable STAB move. Flash Cannon hits Fairy-types like Enamorus, Mega Gardevoir, and Clefable. Fire Blast threatens Celesteela, Tangrowth, and Bisharp, Roost takes advantage of forced switches and lets Hydreigon stay healthy to switch in several times throughout the match, while U-turn lets it pivot out of foes it can struggle against such as Azumarill and Clefable. A Timid nature lets Hydreigon outspeed Excadrill, while Modest gives Hydreigon even more power. Hydreigon struggles to break through Fairy-types such as Azumarill and Clefable, as well as Celesteela if not running Fire Blast, so teammates that can pressure them like Thundurus and Mega Venusaur are helpful. Hydreigon also appreciates pivots such as Victini and Slowking that can safely get it onto the field; Victini can use U-turn to pivot out of switch-ins that Hydreigon threatens like Slowbro and Mega Venusaur, while Slowking can safely pivot it in with Teleport. Knock Off support from the likes of Mega Vensaur, Clefable, and Thundurus is appreciated to help Hydreigon break through Pokemon like Celesteela and Assault Vest Tangrowth. Setup sweepers like Booster Energy Iron Moth and Galarian Moltres benefit from Hydreigon's longevity and ability to pressure their checks such as Mega Venusaur and Tyranitar, respectively, allowing them to become wincons late-game; fast teammates such as Choice Scarf Enamorus and Keldeo also appreciate Hydreigon for this reason, with it being able to pressure their switch-ins such as Slowking and Assault Vest Tangrowth, which can open the way for them to clean late-game. Hydreigon can also easily be revenge killed by faster Pokemon such as Hawlucha, Alakazam, and Enamorus; Skarmory can deal with Hawlucha while providing Spikes support, and Celesteela can deal with Alakazam and Enamorus.