Necrozma-Dusk-Mane @ Sitrus Berry Ability: Prism Armor Level: 50 EVs: 252 HP / 252 Atk / 4 SpD Brave Nature IVs: 0 Spe - Trick Room - Swords Dance - Sunsteel Strike - Earthquake
Necrozma-Dusk-Mane @ Sitrus Berry Ability: Prism Armor Level: 50 EVs: 252 HP / 252 Atk / 4 SpD Brave Nature IVs: 0 Spe - Trick Room - Swords Dance - Sunsteel Strike - Earthquake
Necrozma-Dusk-Mane @ Weakness Policy Ability: Prism Armor Level: 50 EVs: 148 HP / 252 Atk / 108 Spe Adamant Nature - Sunsteel Strike - Earthquake - Rock Slide - Protect
Life Orb can be used instead of Sitrus Berry on set 1. You could also drop Swords Dance for Protect or a 3rd coverage move - if you do, Life Orb or Weakness Policy are generally better items to use. EVs on the second set let you outrun Zacian-C in Tailwind.