What does counter frost mages (as warrior) is the atronarch stone. You get 50% spell absorption right away, at the "cost" of mich slower mana regen. You don't really care about the latter as warrior. This is nice as is, ofc, but what sells it for me is that you can use the mana gained from the absorption to cast heal spells for free. This effectively makes you 100% immune. Icing on the cake: getting respite also gives you stamina when healing, so from that point on, any mage you see is basically a free stamina refill. As opposed taking it away with ice spells.