So.... with 100 Runic Power (a full bar of it), this will silence / completely CC a target for 20 seconds.... That's assuming that the DK doesn't have
Unleashes all available runic power to suddenly purge the earth around the Death Knight of all heat. Enemies within 10 yards are trapped in ice, preventing them from performing any action for 1 sec per 5 runic power. Enemies are considered Frozen, but any damage will break the ice.
(Talent: Frost: Tier 11) (Rank 1) (Instant)
So.... 130 Runic Power = 26 seconds?
Runic Power Mastery 3/3
Runic power abilities with a fixed cost are reduced in cost by 9 and scaling runic power abilities behave as if you had an additional 30% runic power.