I've been trying to think of some Ice based classes, but I can only really think of a couple Supers:
Avalanche - Titan, increased speed, melee charge with AOE freezing/stun effect for nearby enemies
Ice-Sickle - Warlock, increase speed, thrown projectile, ice scythe with Freezing/stun stun effect
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I admit these aren't great, but I would love an Ice based sub-class at some point.