This is a set I've found works well in the Battle Tower, mostly doubles. I haven't used it in Online Battles yet.
Arctovish @ Focus Sash
Ability: Ice Body
EVs: 252 Atk / 128 Def / 128 SpD
- Avalanche / Icicle Crash
- Liquidation / Fishious Rend
- Iron Head
- Psychic Fangs
This Arctovish can usually take two or three super-effective hits before going down, so it can get a boost on Avalanche at least that many times. I would give it a Focus Sash in case it runs into any particularly strong special attackers equipped with its weaknesses though, so it can still get one Avalanche in.
Liquidation could be swapped for Fishious Rend if you wanted to run a Jolly, Slush Rush Arctovish that might have a chance of out-speeding some slower Pokémon. I find Liquidation is a reliable physical move for sluggish little Arctovish though, and it has a chance to lower the opposing Pokémon's defense.
Psychic Fangs and Iron Head are coverage, with Iron Head being a good way to deal with opposing ice types too.
If Arctovish is paired with a speedier partner Pokémon that can dispatch threats against it - and maybe even set up Hail for it - I imagine the Focus Sash could just be replaced with Leftovers so it has extra recovery with Hail.