Arcane Bombardment

You build up a burst of magical energy and arc it toward a target within range. All creatures within a 15ft radius must make a Dexterity saving throw, taking 4d8 force damage on a failed save, or half as much damage on a successful one. When casting this spell you may choose to delay its impact for up to four rounds, when doing so the spell takes a place in the initiative order immediately after you. In addition the spell's radius and damage increase by 5ft and 2d8 respectively for each round delayed.

At higher levels: When you cast this spell using a spell slot of 5th level or higher, the spell's base damage increases by 1d8 and the range of the spell increases by 150 feet each slot level above 4th.