Dagan's Vicious Mockery

The love you have for your enemies' downfall knows no bounds. When a hostile creature you can see rolls a critical failure on ana attack or action, you taunt them with a string of magically imbued insults dealing 2d6 psychic damage and forcing them to make a charisma saving throw. On a failure, the target has disadvantage on their next attack roll. 

This spell's damage increases by 1d6 when you reach 5th level (3d6), 11th level (4d6), and 17th level (5d6).