Forretress (M) @ Leftovers Trait: Sturdy
EVs: 252 HP / 4 Def / 252 SDef
Sassy Nature (+SDef, -Spd)
- Rapid Spin
- Hidden Power [Bug]
About as reliable as a spikes user comes. Can also provide Rapid Spin support for the team, obviously. Forretress can set up on Blissey, Regice, Swampert, non-FB Snorlax, Physical Ttar, and provide a pivot for switching out.
Another way to approach the team might be to pick the Spiker later judging by how the rest of the team is shaping up. Just for consideration.