My guess for this team is...
!
Mesprit @ Choice Scarf
Ability: Levitate
EVs: 4 Def / 252 SpA / 252 Spe
Modest Nature
- Psychic
- Ice Beam
- U-turn
- Healing Wish
This thing supplies the team with a couple things. First of all, it gives an alternate switch in for Fighting and Ground types, if Swanna just isn't feeling it. Next, it gives some speed control, along with forming a Voltturn core with Zebstrika. Lastly, it supplies Healing Wish, which can help Faticate or Carracosta get a potential second chance to sweep, heal up Zebstrika's Life Orb recoil, or give little Golem another chance to wall.