Recently, most of the volcaronas I've seen are bulky, so it's not a lost cause. Still, I think CB and SD haxorus are the most threatening...
Especially the CB variants for packing extreme amounts of power. A CB Rivalry-boosted Outrage is nothing to joke about (It helps that very few people change their Poke's genders.) Mold Breaker's also an excellent ability, for trolling Earthquake switchins like Gengar and Bronzong.
Some damage calcs for a Rivalry variant, assuming a boost from his ability (Neutral natures assumed unless stated otherwise)
Outrage vs max/max Gyarados Intimidate: 648 Atk vs 282 Def & 390 HP (150 Base Power): 370 - 436 (94.87% - 111.79%) (66% chance of a OHKO without rocks, guaranteed otherwise)
Brick Break vs standard 252/48 Ferrothorn: 648 Atk vs 336 Def & 352 HP (93 Base Power): 258 - 304 (73.30% - 86.36%) (Guaranteed 2HKO)
Outrage vs max/min Tyranitar: 648 Atk vs 256 Def & 404 HP (150 Base Power): 408 - 480 (100.99% - 118.81%) (OHKOed)
Earthquake vs max/min Scizor: 648 Atk vs 236 Def & 344 HP (125 Base Power): 246 - 290 (71.51% - 84.30%) (2HKOed by everything, but Earthquake can KO after the first switch into Stealth Rock)
Outrage vs 252/200 Impish Gliscor: 648 Atk vs 370 Def & 354 HP (150 Base Power): 282 - 333 (79.66% - 94.07%) (Low chance of a OHKO with SR, but it won't like the hit anyway)
Something vs max/max Skarmory: 648 Atk vs 416 Def & 334 HP (150 Base Power): 126 - 148 (37.72% - 44.31%) (Painfully a 3HKO at best, that's assuming average damage rolls vs Leftovers)
These are just some examples of the sheer firepower behind this thing, against some of the most-used threats out there. Notably, he loves Spikes and Stealth Rock support, as it'd push some things into KO range for him, like Ferrothorn and Scizor. Add in the ability to sponge incoming Ice and Dragon attacks, and I'd think Ferrothorn would make an excellent partner for him. You just need to find a way to get rid of Skarmory. Magnezone can trap the non-Shed Shell variants, otherwise you'll just have to KO him through other means.
Honestly, if you're not a Steel type, you'll hate an Outrage from this thing.