Arcane Onslaught

Your weapon hums with arcane energy, ready to cleave through enemies in a destructive wave. Until the spell ends, once per turn when you take the Attack action, you can replace one of your attacks with an empowered strike.

Choose a target within your weapon’s reach. On a hit, the target suffers normal weapon damage plus 1d8 force damage, and the energy lashes out in a 30-foot line, 5 feet wide. Each creature in the line must make a Dexterity saving throw, taking 1d8 force damage on a failure, or half on success.