>>22358383Because
0- Atk Life Orb Sheer Force Nidoking Poison Jab vs. 252 HP / 232 Def Florges: 276-328 (76.6 - 91.1%) -- 25% chance to OHKO after Stealth Rock
252 SpA Life Orb Sheer Force Nidoking Sludge Wave vs. 252 HP / 24+ SpD Florges: 242-289 (67.2 - 80.2%) -- guaranteed 2HKO after Stealth Rock and Leftovers recovery
0- Atk Life Orb Sheer Force Nidoking Poison Jab vs. 4 HP / 252+ Def Blissey: 242-286 (37.1 - 43.8%) -- guaranteed 3HKO after Stealth Rock and Leftovers recovery
252 SpA Life Orb Sheer Force Nidoking Sludge Wave vs. 4 HP / 252 SpD Blissey: 126-149 (19.3 - 22.8%) -- possible 5HKO after Stealth Rock and Leftovers recovery
You could argue Sylveon, but Nidoking isn't that good in VGC, when Nidoqueen is better there and that it's outclassed by Landorus-I in OU, the only place you should be really using Nidoking is UU
