Arcane Burst

You react to a creature beginning an attack by launching a hindering ball of force at the creature.  Resolve this spell attack prior to resolving the creature's attack(s).

Make a ranged spell attack at the target.  If hit, the target takes 2d6 force damage and has disadvantage on the next attack it makes before the end of its turn.  If the spell attack misses, no damage or effect is applied.  Once this reaction has been resolved and applied, continue resolving the attack(s) being made by the creature targeted by this spell.

At higher levels, the damage increases by 1d6 per spell level.