Deadly Vibration

You reach out your hand causing a creature to Vibrate violently. The creature must make a Con saving throw or suffer 5d4 thunder damage and has disadvantage on attacks and ability checks relying on Dexterity and Strength until the end of its next turn. On a success the creature takes half as much damage and does not suffer the disadvantage.  Whether the creature succeeds or fails they must repeat this saving throw at the end of its next turn, but the damage is reduced by 1d4 on each subsequent turns. This continues until you lose concentration, or the damage is reduced to 0d4.

Heightened: For each level beyond 4 that this spell is cast at increase the damage by 1d4.