Echoes of Steel

4th-level evocation

Casting Time: 1 bonus action
Range: Self (30-foot radius)
Components: S
Duration: Concentration, up to 1 minute

When you hit a creature with a melee weapon attack, you can use a bonus action to cast echoes of steel. All creatures you designate within 30 feet of you take thunder damage equal to the damage from the melee attack, or half as much damage with a successful Constitution saving throw.