If anyone saw that battle against insanelegend, my Kyurem-Black put in some work. It's a gen 5 set (as is the team) but I think it still might be worth testing further. I don't really know what the standard Kyurem-B set is actually, so maybe this is already close to it.
Kyurem-Black @ Lum Berry / Leftovers
Ability: Teravolt
EVs: 52 HP / 204 Atk / 252 Spe
Jolly Nature
- Dragon Dance
- Substitute
- Roost / Fusion Bolt
- Icicle Crash / Icicle Spear
The spread gives you max Speed and 101 HP substitutes. Basically, throw up a Sub as quickly as possible and start dancing. The Lum is nice in case you want to sub on Sableye, who will try to Dark Void or Will-O-Wisp you first most of the time. If it Taunts, switch and come back in later. Leftovers are a good option if you don't run Roost. The great thing is this set is immune to Topsy behind a sub. Parting Shot will still work, however. Also, Quagsire can't stomach hits at +1 because Teravolt nullifies Unaware.
Another option:
Kyurem-Black @ Life Orb / Choice Band
Ability: Teravolt
EVs: 4 HP / 252 Atk / 252 Spe
Jolly / Adamant Nature
- Ice Shard
- Fusion Bolt
- Dragon Claw
- Icicle Crash / Icicle Spear
In a world where Landorus and Thundurus threaten to undo everything that is sacred in STABmons, there is a hero named Kyurem-Black. Ice Shard is a great move for sniping them and fellow birds giving your team troubles. I prefer Life Orb because you really don't want to get locked into Dragon Claw on a Fairy or Steel-type.
Jolly:
-1 252 Atk Life Orb Teravolt Kyurem-B Icicle Crash vs. 252 HP / 252+ Def Landorus-T:
458-546 (119.8 - 142.9%) -- guaranteed OHKO
-1 252 Atk Life Orb Teravolt Kyurem-B Ice Shard vs. 252 HP / 252+ Def Landorus-T:
218-265 (57 - 69.3%) -- guaranteed 2HKO after Leftovers recovery
252 Atk Life Orb Teravolt Kyurem-B Ice Shard vs. 252 HP / 252+ Def Landorus-T:
328-390 (85.8 - 102%) -- 6.3% chance to OHKO
252 Atk Life Orb Teravolt Kyurem-B Ice Shard vs. 0 HP / 4 Def Landorus:
452-536 (141.6 - 168%) -- guaranteed OHKO
252 Atk Life Orb Teravolt Kyurem-B Ice Shard vs. 0 HP / 4 Def Thundurus:
281-330 (93.9 - 110.3%) -- 62.5% chance to OHKO (obviously OHKO w/ Rocks)
252 Atk Life Orb Teravolt Kyurem-B Ice Shard vs. 0 HP / 4 Def Togekiss:
218-257 (70 - 82.6%) -- 62.5% chance to OHKO after Stealth Rock
252 Atk Life Orb Teravolt Kyurem-B Ice Shard vs. 0 HP / 4 Def Yanmega:
237-281 (75.7 - 89.7%) -- guaranteed 2HKO (obviously OHKO w/ Rocks)
252 Atk Life Orb Teravolt Kyurem-B Ice Shard vs. 4 HP / 0 Def Diggersby:
260-307 (83.3 - 98.3%) -- 25% chance to OHKO after Stealth Rock
Adamant:
-1 252+ Atk Life Orb Teravolt Kyurem-B Ice Shard vs. 252 HP / 252+ Def Landorus-T:
239-286 (62.5 - 74.8%) -- guaranteed 2HKO after Leftovers recovery
252+ Atk Life Orb Teravolt Kyurem-B Ice Shard vs. 252 HP / 252+ Def Landorus-T:
348-421 (91 - 110.2%) -- 50% chance to OHKO
252+ Atk Life Orb Teravolt Kyurem-B Ice Shard vs. 0 HP / 4 Def Thundurus:
307-361 (102.6 - 120.7%) -- guaranteed OHKO
252+ Atk Life Orb Teravolt Kyurem-B Ice Shard vs. 0 HP / 4 Def Togekiss:
242-283 (77.8 - 90.9%) -- guaranteed OHKO after Stealth Rock
252+ Atk Life Orb Teravolt Kyurem-B Ice Shard vs. 0 HP / 4 Def Yanmega:
260-307 (83 - 98%) -- guaranteed 2HKO (obviously OHKO w/ Rocks)
252+ Atk Life Orb Teravolt Kyurem-B Ice Shard vs. 4 HP / 0 Def Diggersby:
283-338 (90.7 - 108.3%) -- 81.3% chance to OHKO after Stealth Rock
It can also land a nice 1-2 on a fully defensive Sableye with Icicle Crash+Ice Shard:
252 Atk Life Orb Teravolt Kyurem-B Icicle Crash vs. 252 HP / 252+ Def Sableye:
191-226 (62.8 - 74.3%)
252 Atk Life Orb Teravolt Kyurem-B Ice Shard vs. 252 HP / 252+ Def Sableye:
91-109 (29.9 - 35.8%)
92.7 - 110.1% -- 94% chance to OHKO after Stealth Rock and Leftovers recovery