"Freezes the enemy defensive towers solid for 10 seconds. The affected towers cannot attack"
Ice Shards is similar to a catapult attack and works exactly the same as one. All towers in its range marker will get frozen and be unable to attack for the 10 seconds duration. This only affects towers, it does not affect Watch Posts and/or beasts. Ice Shards can be produced in the Blacksmith
Ice Shards is an Event Item which can only be unlocked at the Event Store. You will need to gain Event Points in the Event to be able to unlock the Event Items.