Chilling Curse

You call forth spirits of winter and darkness to try and curse your enemies.

Choose a location within range - a 15 ft. cube centered on the location you choose is filled with a tempest of chilling spirits. All creatures within the cube take 4d8 cold damage, and must make a Charisma saving throw. On a failure, a creature is cursed by chilling spirits. While cursed in this way, a creature has a -3 penalty to all saving throws it makes - if a creature fails a saving throw while cursed in this way, it takes 2d8 cold damage, and the penalty to saving throws is reduced by 1.

The curse on a creature ends if its saving throw penalty is reduced to 0, or if the Remove Curse spell is cast on it.