(Gen 9) National Dex Monotype All-Out-Attacker (Dragon)

Latios (M) @ Latiosite
Ability: Levitate
Tera Type: Dragon
EVs: 4 Atk / 252 SpA / 252 Spe or 252 SpA / 4 SpD / 252 Spe
Naive / Timid Nature
- Luster Purge
- Ice Beam
- Thunderbolt
- Earthquake / Mystical Fire
An AoA set Mega Latios can use on Dragon teams in Gen 9 National Dex Monotype. Mega Latios has been seeing more usage on Dragon thanks to its Ground immunity and ability to deal with a variety of matchups thanks to different coverage moves it can choose to use. Luster Purge is the STAB move used on this set, being useful against Poison- and Fighting-types such as Toxapex, Galarian Weezing, Mega Venusuar, Kommo-o, Keldeo, and Urshifu-Rapid-Strike. Luster Purge's 50% chance to drop the Special Defense stat of opposing Pokemon is useful to help with Mega Latios wallbreak better. Ice Beam and Thunderbolt form the infamous BoltBeam combo, being useful to handle the Ground, Water, Dragon, and Flying matchups. Ice Beam is useful to target Pokemon such as Gliscor, Landorus/Landorus-Therian, Garchomp/Mega Garchomp, Zapdos, Roaring Moon, Dragonite. Thunderbolt lets Mega Latios hit Water- and Flying-types such as Celesteela, Corviknight, Mantine, Hisuian Samurott, and Greninja. Earthquake allows Mega Latios to deal super effective damage to Heatran (once its Air Balloon is popped if it has Air Balloon), Alolan Muk, Hisuian Goodra, and Galarian Slowking. Mystical Fire can be an option if you want to get rid of Scizor/Mega Scizor and Ferrothorn.
Naive Nature is used if you use Earthquake. Timid Nature is used if you use Mystical Fire. You should also use the second EV spread listed if you use Mystical Fire. You can still use Timid Nature with the first EV spread, but it does make Earthquake deal less damage, meaning you miss out on stuff like a guaranteed 2HKO vs Galarian Slowking. An alternative set you could run with the first EV spread with Naive Nature is Luster Purge/Mystical Fire/Earthquake/Roost, with Roost being useful for longevity.