Gen 9 Monotype Defog (Dragon)

Noivern @ Heavy-Duty Boots
Ability: Frisk
Tera Type: Flying
EVs: 252 HP / 4 SpA / 252 Spe or 252 SpA / 4 SpD / 252 Spe
Timid Nature
- Hurricane / Air Slash
- Defog
- Roost
- U-turn / Flamethrower / Taunt / Super Fang
With hazard removal being quite limited for Dragon teams, Noivern soars above the options for hazard removal, and for good reason. Cyclizar has awkward synergy with Dragon teams, and Tatsugiri and Altaria aren't good in Monotype. The things Noivern offers to a Dragon team is an appreciated Ground immunity, a fast Pokemon that can outspeed and get rid of Iron Valiant, and a Pokemon who has some neat utility moves to help out the team.
Hurricane is the STAB move for this set since it OHKOs Iron Valiant, who is a threat to Dragon teams. Air Slash can be used for an alternative Flying STAB with better accuracy at the cost of lower power. Defog is used to clear away hazards, which is useful for teammates who aren't using Heavy-Duty Boots so they don't have to worry about taking hazards damage as much. Roost is used to give Noivern reliable HP recovery so it can stick around longer. U-turn allows Noivern to switch out and bring in a teammate. Flamethrower is an option to hit Steel-types such as Corviknight, Gholdengo, Scizor, and Iron Treads super effectively, being useful to deter Gholdengo from switching in to prevent a Defog. Taunt allows Noivern to shut down defensive Pokemon such as Toxapex and Clodsire, as well as slower setup Pokemon trying to setup. Super Fang is a neat option to wear down defensive Pokemon such as Archaludon, Heatran, Hisuian Goodra, Blissey, and Clodsire.
The EV spread you use depends on which Flying STAB you use. If you use Hurricane, use the EV spread of 252 HP / 4 SpA / 252 Spe since it doesn't need to invest EVs to make Hurricane an OHKO against Iron Valiant. If you use Air Slash, use the EV spread of 252 SpA / 4 SpD / 252 Spe since Air Slash needs Special Attack EVs invested to OHKO Iron Valiant. If you want a little bulk on the offensive spread, you can do 48 HP / 208 SpA / 252 Spe, which has enough Special Attack EVs for Air Slash to have a guaranteed OHKO against Iron Valiant.