Manipulator

You gain proficiency in the persuasion and deception skills. If you already have proficiency, you gain expertise. 

You can spend an action to talk to someone and systematically undermine their self-confidence. This effect stacks. The target must make a Charisma saving throw with a DC of 8 + your proficiency bonus + your charisma.

On a failure, the victim takes a -1d4 to all rolls for the next two turns. On a success, the DC of the saving throw decreases by 1 for that target only for the next hour.