(2 items) When you deal Critical Damage, you have a 20% chance to gain a damage shield that absorbs 8300 damage for 6 seconds. While the damage shield holds, you deal 743 Cold Damage to all enemies within 5 meters of you every 1 second. This effect can occur once every 6 seconds.
Using the motifs for the shoulder/mask is how you get them with the frost like effect.