Ice Queen, called Counter Mastery before being unlocked, is a passive skill unique to Weiss Schnee in RWBY: Grimm Eclipse. It needs to be unlocked by successfully countering enemies 300 times as Weiss. When used, it will freeze the enemy in addition to the damage. Costs 1 point to use.
As Boarbatusks cannot be frozen, countering them with this ability will not Stun them either, basically only dealing the damage and interrupting them.
During Early Access, Ice Queen was called Master Blaster before being unlocked, and was unlocked by killing 20 enemies with blast attack (done by performing a ranged attack during a melee combo). This skill upgrades Weiss' blast attack to freeze all enemies hit by the attack for 3 seconds.