Takes One to Know One

You sing a simple melody that seems to resonate with a hidden power. When you cast this spell, choose a creature or player within range other than yourself. The creature or player must make a Charisma saving throw. On a failed save, the creature or player has disadvantage on their next ability check, attack roll, or saving throw, or you can roll a 1d6 and subtract the result from their next ability check, attack roll, or saving throw. If the effect is successful, you also suffer the same effects of the spell with them.