If you've played Nat Dex within the past month or so, then you've probably lost to this set before.
National Dex
Cinderace @ Normalium Z
Ability: Libero
EVs: 252 Atk / 4 Def / 252 Spe
Jolly Nature
- Pyro Ball
- Double-Edge
- Bulk Up
- Sucker Punch / High Jump Kick / Gunk Shot / Substitute
Pyro Ball allows Cinderace to get rid of Steels like Corviknight, Ferrothorn, and Magearna. Double-Edge is already strong enough by itself, however with STAB, Normalium Z, and a potential Bulk Up it becomes almost impossible to switch into, overwhelming usual checks like Toxapex, Clefable, and NDOU's resident Ground types, especially after hazard chip.
Bulk Up boosts Cinderace's Attack, and the Defense boost is nice. Sucker Punch revenge-kills faster Pokemon and kills the rare Ghost types, including the Scald-clicking Jellicent which is rising in order to counter standard variants of this set.
High Jump Kick gets rid of Heatran and Tyranitar, both of which resist Normal and either resist or, in Flash Fire Heatran's case, are immune to Fire. Gunk Shot hits Clefable hard without wasting Normalium Z and can spread Poison. Substitute lets Cinderace set up Bulk Up more easily, and makes it immune to Intimidate.