Wand Focus: Frost is a Wand Focus/Research subtitled "Revenge is a dish best served cold", and available for research after researching Wand Foci.
Right clicking with this Focus equipped will shoot out a small icy ball, as well as drain you of 2 Aqua, 1 Ignis, and 2 Perditio vis. These balls bounce off solid objects with normal physical rules a couple times before shattering. Hitting any damageable entity (including yourself) will damage them. Holding down the fire button will release balls continuously, meaning you can rapid fire them.
Crafting a Wand Focus: Frost requires an Arcane Workbench. To do so, place a diamond in the center, bordered by nether quartz, with Water Shards in the corners. You must then spend 150 Aqua, 150 Ordo, and 100 Perditio vis to craft it.