This is the set I'll be running. You only need 3 perfect IV's with it too (HP, Def, SpD), 4 (speed) if you'd really like I guess. I'd recommend bold nature over calm because ground/fighting attacks are more common than fire. You can go with either nature depending on what works best with your team though.
Klefki @ Focus Sash or Mental Herb Bold 252 HP /128 Def / 128 Spdef Toxic Foul Play Torment Protect