Hawlucha serves as an offensive Check to Urshifu-SS.

Hawlucha @ Grassy Seed
Adamant Nature
Ability: Unburden
EVs: 252 Atk / 28 Def / 228 Spe
- Swords Dance
- Acrobatics
- Close Combat
- Roost/Taunt/Substitute
It is able to do so thanks to its unique typing. Defensively, Lucha’s type lets it resist Urshifu’s duel STAB without fear of a super-effective Poison Jab. It then has the option to either attempt to revenge kill Urshifu-SS through Close Combat or to set up Swords Dance. Offensively, Lucha is faster and can OHKO Urshifu-SS through CC 93.8% of the time. Meanwhile, should that 6.2% chance come to be, Grassy Seed neutralizes the stat drop to Defense and Urshifu-SS always 2HKOs Lucha at neutral meaning the Grassy Seed ensures the 1v1 without CC crits.
It is also worth noting that in addition to winning 1v1, Lucha can abuse Urshifu-SS to start setting up with SD to either +2 if it Wicked Blows, switches out, or gets a good roll on CC, or +4 if it doesn’t win that roll (the reason I gave it some Defense instead of max/max). Lucha can then use its Attack boosts courtesy of Urshifu-SS to start sweeping or wall-breaking. Also last move doesn’t matter, use whatever you prefer.
252+ Atk Hawlucha Close Combat vs. 0 HP / 4 Def Urshifu: 338-402 (99.1 - 117.8%) -- 93.8% chance to OHKO
252+ Atk Choice Band Urshifu Close Combat vs. +1 0 HP / 28 Def Hawlucha: 132-156 (44.4 - 52.5%) -- 18.4% chance to 2HKO
252+ Atk Choice Band Urshifu Close Combat vs. 0 HP / 28 Def Hawlucha: 197-232 (66.3 - 78.1%) -- guaranteed 2HKO
252+ Atk Choice Band Urshifu Wicked Blow vs. 0 HP / 28 Def Hawlucha on a critical hit: 197-232 (66.3 - 78.1%) -- guaranteed 2HKO