I use an pretty standard set for OU (IMO, Cobalion has OU potential)
Cobalion@leftovers
Jolly: 140 HP/ 136 ATK/ 232 Spe
Close Combat
Taunt
Swords Dance
X-scissor
Its main purpose is to clean up after you have taken care of threats such as skarmory, jellicent, and Gliscor. If you can get a free...