"When you taunt an enemy, you have a 50% chance to cause a duneripper to burst from the ground beneath them, dealing 6500 Physical Damage to all enemies within 4 meters and reducing their Movement Speed by 70% for 8 seconds. This effect can occur once every 4 seconds."
A heavy ice staff attack taunts....so it should work, but I havent actually tried it. Why use an ice staff though? better off using inner fire if thats your thing...more damage and has both a stam and magicka morph, and an instant cast, plus a synergy for allies(albeit a pretty bad one, but maybe they are waiting for regen or something, the synergy is a mini vicious death)
I actually used to use red mountain on my magsorc a long time ago. The extra proc was like a free hidden frags cast, netted a lot of surprise kills. It's not super reliable though.
ya more of a hybrid build pair it with necro and tremor scale double proc stun all ranged
You're on the right track, though tremor is a little harder to use. The biggest issue with proc sets in general, is that they're unreliable. If they all go off, you have damage that is either just under, at, or just over meta build damage when you're considering burst.
If they don't go off?
People tend to forget that when they complain about them.
Keep experimenting with them, look at other ways to get the damage you need, and you might just surprise yourself and stumble on something wonderful. I did. =D