Honestly, I would use this for a Black Kyurem:
Kyurem-Black @ Choice Band
Ability: Teravolt
EVs: 252 HP / 252 Atk / 4 Spe
Adamant Nature
- Outrage / Dragon Claw
- Fusion Bolt
- Freeze Shock / Ice Beam
- Sleep Talk
This set is simple: sit back, relax, and spam Outrage. Or you can run Dragon Claw for less power but the freedom to switch. However, even Defensive Landorus-T is 2HKOed by Outrage. Fusion Bolt is for coverage against bulky steel types, except Ferrothorn. If your opponent dares to switch, and you predict them, Freeze Shock hits so hard, it does half to Toxapex. However, Ice Beam could be used to be reliable ice STAB. Sleep Talk is used to be a sleep sponge.
The EVs are to nuke your opponents with overpowered physical attacks, while make use of Kyurem-Black's good bulk. Teravolt is the only ability Kyurem-B can have, and is a good one to, allowing Kyurem-Black to ignore abilities like sturdy and disguise. Finally, an Adamant nature is used to... well, it’s kind of obvious.
Hope this shreds many teams!
Calculations:
252+ Adamant Kyurem-B Fusion Bolt vs 252/252+ Skarmory: 248-292
(78.2-88%) Guaranteed 2HKO.
252+ Adamant Kyurem-B Outrage vs 252/252+ Zygarde-C: 498-588
(78.3-92.4%) Guaranteed 2HKO after Leftovers recovery.
(Not many Pokemon can do that with a physical move)
252+ Adamant Kyurem-B Freeze Shock vs 252/0 Aegislash -Shield: 162-191
(50-58.9%) Guaranteed 2HKO
252+ Adamant Kyurem-B Freeze Shock vs 252/252+ Eviolite Chansey: 610-718
(86.6-101.9%) 12.5% chance to OHKO.
(Note: These are some of the bulkiest Pokemon in the game)