Thunderous Strike

You brandish the weapon used in the spell’s casting and make a melee attack with it against one creature within 5 feet of you. On a hit, the target suffers the weapon attack’s normal effects and then must make a strength saving throw or be pushed 10ft away from you. A creature that is more than one size larger than you automatically succeeds on the saving throw. Whether the target succeeds or fails their save, the sound of rolling thunder resounds from the point your weapon made contact and can be heard from 100ft away.

This spell deals additional damage at higher levels. At 5th level, the melee attack deals an extra 1d8 thunder damage to the target on a hit. This extra damage increases by 1d8 at 11th level (2d8) and again at 17th level (3d8).