I’ve been designing spells for something secret and reading the Sword Coast Adventurers Guide. Let’s combine those two.
Casting Time: 1 action
Range: 5 feet
Components: V, M (a weapon)
As part of this action used to cast this spell, you must make a melee attack with a weapon against one creature within the spell’s range, otherwise the spell fails. On a hit the target suffers the attack’s normal effects, and a sonic boom infuses the area. That creature must make both a Strength and Constitution saving throw. If it fails the Strength saving throw, the creature is moved 5 feet away, knocked prone, and you are no longer considered engaged if the creature does not have reach to attack you with one of its melee weapons. If it fails the Constitution saving throw, the creature is dealt an extra 1d4 thunder damage.
This spell’s damage and thrown distance increases when you reach higher levels. At 5th level, the spell’s thunder damage increases to 2d4 and the thrown distances increases to 10 feet. The distance increases to 15 feet and 3d4 thunder at 11th level, and to 20 feet and 4d4 thunder at 17th level.