I have One moon stone, and only one option. I own a Nidorino and a Clefairy, and the rest of the team, not including the Nidorino and Clefairy is as follows:
PlantBoi (Ivysaur) (M) Lv. 17 StingyBoi (Beedrill) (F) Lv. 15 KarateBoi (Mankey) (M) Lv. 16
Any help would be appreciated. Thanks!
Nidoking by a massive margin. It's stronger and faster than Clefable, plus it learns excellent moves that make it an incredibly valuable team member for quite some time. Clefable definitely works, but it just can't match the sheer power of Nidoking, especially in the early game. Evolve it before Level 22, as that's when it learns Thrash.
Nidoking Ability: Poison Point - Thrash - Earthquake / Dig - Megahorn - absolutely anything
Hope I helped!