gO! (Mawile) @ Life Orb
Ability: Sheer Force
EVs: 252 Atk / 4 SpA / 252 Spe
Naughty Nature
- Play Rough
- Iron Head
- Fire Blast
- Sucker Punch
Sumo (Poliwrath) @ Choice Specs
Ability: Water Absorb
EVs: 96 HP / 252 SpA / 160 Spe
Modest Nature
IVs: 0 Atk
- Scald
- Focus Blast
- Ice Beam
- Vacuum Wave
Sanic (Sandslash) @ Lum Berry
Ability: Sand Rush
EVs: 132 HP / 252 Atk / 124 Spe
Adamant Nature
- Rapid Spin
- Earthquake
- Stone Edge/Knock off
- Swords Dance
So this core basically focuses on the wallbreaking capabilities of these underrated NU mons, as SpecsPoli deals a lot of damage when it's checks and counters are gone. I chose mawile cause it deals with specially defensive pokemon like sliggoo,yama, and lanturn, while also luring gastro, and at the right predict, has a high chance to 2HKO with Play Rough. Sandslash on the other hand, is a pretty cool spinner, and plows through bulk teams through SD, also to the help of mawile removing the likes of gastro.
Also, despite this core has sandslash, it has problems with electric types, especially lanturn, as well as a lot of special attackers in the tier. Make sure to give the core a solid backbone that mitigates those weakness, while keeping the offensive momentum.
Edit: Still thinking Sandslash wasn't perfect for this, and thinking this post highlights more on mawile+poli, and sandslash's underrated capabilities