I had the idea to try a Scarf Volcarona set in the past, but never tried it in practice; it could work very well, if you manage to keep rocks off the field. Anyway, since you just defeated me, it's safe to post this set...

Landorus-I @ Life Orb
Trait: Sheer Force
4 HP / 252 SpA / 252 Spe
Nature: Timid
- Stealth Rock
- Earth Power
- Psychic / Focus Blast
- HP Ice
It's basically the Special Attacker set onsite, but with a supporting twist since it can set up Rocks. Basically works like SR Terrakion, a tad slower, but with a much better defensive typing and resilience to hazards. Landorus forces lots of switches with its sheer power or the threat of a Scarf EQ / U-Turn, thus giving it plenty of time to throw SR onto the field. Its coverage is not too badly crippled by losing a slot, especially if your team already handles well Steel types (so you don't have a desperate need to run Focus Miss).