Iceblink

Weapon (any sword), rare (requires attunement)

The blade of this weapon is cool to the touch and gives off a yellow-white radiance, shedding bright light in a 10‑foot radius and dim light for an additional 10 feet. In temperatures above freezing, vapor wafts off the chilled blade. When you hit with an attack using this magic sword, the target takes an extra 1d6 cold damage.

Freeze Water. While holding the sword, you can use an action to plunge the blade into a body of water, causing its surface to freeze over. The water freezes to a depth of 3 inches within a 60-foot radius of the point where you plunged the blade. Creatures that were swimming on the surface of the water must succeed on a DC 15 Dexterity saving throw or be restrained by the ice. A restrained creature can use an action to make a DC 15 Strength check, breaking free on a success. The ice is not magical and melts after 1 minute if temperatures in the area are not cold enough to sustain it. Once used, this property can’t be used again until the next dawn.

Snowblind. While holding the sword, you can use an action to generate a bright flash of light from the blade at one creature you can see within 5 feet of you. The target must succeed on a DC 15 Constitution saving throw or be blinded for 1 minute. The creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. Once used, this property can’t be used again until the next dawn.