Arceus-Grass @ Meadow Plate
Ability: Multitype
EVs: 248 HP / 240 SpD / 20 Spe
Calm Nature
IVs: 0 Atk
- Grass Knot
- Ice Beam
- Recover
- Roar / Perish Song
The Best-Ogre-Check-in-the-Game™ makes another appearance as one of the best Glare-Coil Zygarde counters in the game. +6 Zygarde does nothing to even SpDef Arceus-Grass, being that it's a real Ground-resist.
+6 4 Atk Zygarde-Complete Thousand Arrows vs. 248 HP / 0 Def Arceus-Grass: 165-195 (37.2 - 44%) -- guaranteed 3HKO (literally 4)
Meanwhile, Zygarde is nearly always 2HKO'd by Arc-Grass:
0 SpA Arceus-Grass Ice Beam vs. 252 HP / 0 SpD Zygarde-Complete: 316-376 (49.6 - 59.1%) -- 74.2% chance to 2HKO after Leftovers recovery
Grass Knot allows this Arc to also beat Ogre, check Geo Xern, do significant damage to Primal Groudon, and counter most SmashPass teams. There is the possibility that you'll get Glare'd and never move again, but you always have the best counter for that garb in the game: clicking the forfeit button.