Taking HP Ground Volcarona (will write it up after my final exam. Wish me luck! Ü)
Volcarona @ Lum Berry
Ability: Flame Body
EVs: 72 HP / 252 SpA / 184 Spe
Timid Nature
IVs: 0 Atk / 30 SpA / 30 SpD
- Quiver Dance
- Fire Blast
- Giga Drain
- Hidden Power Ground
By replacing Bug Buzz with HP Ground, Volcarona is now able to setup in Heatran's face before OHKO it after two Quiver Dances. The scenario is simple: Volcarona is switched after a sac or from U-turn/Volt Switch/Baton Pass into something it forces out. After that, Volcarona sets up a Quiver Dance as Heatran naturally switches. Then, Volcarona sets up a second Quiver Dance as Heatran either Taunts it (idk why it'd do that, but still...), Toxics it (that's why I put Lum Berry instead of Passho Berry or whatever item one would want to use), sets up SR (predicting a switch, which would've happened if it didn't have HP Ground) or even Lava Plume it (again, predicting a switch) before getting OHKOed (read getting your team swept) by the almighty fire-breathing moth God.
Without HP Ground:
+6 252 SpA Volcarona Bug Buzz vs. 248 HP / 192+ SpD Heatran: 109-129 (28.3 - 33.5%) -- 95.1% chance to 4HKO after Leftovers recovery
With HP Ground:
252 SpA Volcarona Hidden Power Ground vs. 248 HP / 192+ SpD Heatran: 200-236 (51.9 - 61.2%) -- 92.2% chance to 2HKO after Leftovers recovery
+2 252 SpA Volcarona Hidden Power Ground vs. 248 HP / 192+ SpD Heatran: 392-464 (101.8 - 120.5%) -- guaranteed OHKO