Adula's Moonblade

You conjure a massive blade of pale, moonlit magic and sweep it outward in a wide arc. Each creature in a 30-foot cone must make a Dexterity saving throw. A creature takes 6d6 cold damage plus 2d6 force damage on a failed save, or half as much damage on a successful one.

Immediately after the sweep, a crescent wave of frost-laced energy travels outward. Creatures that failed the saving throw have their speed reduced by 10 feet until the end of their next turn.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the cold damage increases by 1d6 for each slot level above 3rd.