Dragon check.
Kyurem-Black @ Choice Scarf
Ability: Teravolt
EVs: 252 Atk / 4 SpA / 252 Spe
Naive Nature
-
Ice Beam
-
Outrage
- Iron Head
- Fusion Bolt
Black Kyurem with Choice Scarf appears to be the best Dragon's answer to Dragon Dance Dragonite. I could note non-Scarf Kyurem as well, but it gets obliterated if Dragonite manages to Dragon Dance once beforehand.
The reason why exactly Choice Scarf set is the best answer to it is because such Black Kyurem is faster than +1 Dragonite (it doesn't usually manage to gain more against a Dragon team), bypasses Multiscale thanks to Teravolt and tanks Extreme Speed very well:
+3 252+ Atk Dragonite Extreme Speed vs. 0 HP / 0 Def Kyurem-B: 244-288 (62.4 - 73.6%) -- guaranteed 2HKO
Extreme Speed cannot OHKO Black Kyurem even after Stealth Rock and even if Dragonite managed to obtain Weakness Policy boost and use Dragon Dance once, while +1 one cannot even reach over than 45%
+1 252+ Atk Dragonite Extreme Speed vs. 0 HP / 0 Def Kyurem-B: 147-173 (37.5 - 44.2%) -- guaranteed 3HKO
4 SpA Teravolt Kyurem-B Ice Beam vs. 0 HP / 0 SpD Dragonite: 456-540 (141.1 - 167.1%) -- guaranteed OHKO
252 Atk Teravolt Kyurem-B Outrage vs. 0 HP / 4 Def Dragonite: 498-588 (154.1 - 182%) -- guaranteed OHKO