Arcane Slicer

Mage tenses with pure arcane energy with one arm across his body, his hand is lays fat and he expels the energy with the movement of a horizontal arch. This sends out a horizontal arch of pure arcane energy. Each creature in a 40-foot cone must make a Dexterity saving throw. A creature takes 8d10 force damage on a failed save, or half as much damage on a successful one.