Frozen Razors

Razor-sharp blades of ice erupt from the ground or other surface, filling a 20-foot cube centered on a point you can see within range. For the duration, the area is lightly obscured and is difficult terrain. A creature that moves more than 5 feet into or inside the area on a turn takes 2d6 slashing damage and 3d6 cold damage, or half as much damage if it makes a successful Dexterity saving throw. A creature that takes cold damage from frozen razors is reduced to half speed until the start of its next turn.