Rifles Performance

Using Lomanav's Rifle, you cast a spell. The barrel emanates with power as you cast one spell per short rest. Pointing the rifle at your target, you gain advantage on one attack, and add +1 damage. Spells then become instantaneous, and doesn't use a spell slot. After using the feat, the user must make a dexterity saving throw of 12+. Upon failing the saving throw, the user has disadvantage on all actions for the next 3 turns. Upon succeeding, the user preforms the feat with no disadvantage on the remaining turns.