Not to be confused with Frost Relic from Risk of Rain.
The Frost Relic is a returning item in Risk of Rain 2, having gone from Uncommon to Rare. It is different from its Risk of Rain counterpart in that it surrounds the user with an ice storm, dealing 600% damage per second, with the radius growing 1 meter per kill, up to 6 meters per stack.
Since the area moves with the player and is relatively small, this item is most effective with the melee-focused Mercenary and a ramming MUL-T. Other classes tend to try and stay away from enemies, but flame-spewing Artificers may make good use of this as well.
As with most items, the Engineer's Auto-Turret will inherit this item and surround themselves with a damaging ice field.
The Huntress may want to pass this pickup to a more suitable friend, as her ranged abilities and fragile nature encourage her to keep a distance from enemies.