I'm not sure, though the reasons I would use him are:
He gives a Fighting Type resistance, and Ice types are weak to Fighting.
He will instantly remove opposing Toxic Spikes, which would ruin Wallrein.
He can set up Toxic Spikes, expanding Wallrein's stalling capablities from stalling out 2 pokemon to a whole team(Substitute + Protect give 32 turns of stall, which with Hail damage takes out 2 full health pokemon.With Toxic Spikes making them take more damage though, he can wipe out a whole team before running out of PP.).
He can Knock Off opposing wall's Leftovers, which would otherwise nulify Hail damage.
He will absorb Fire attacks aimed at Abomasnow.