Unhinged

You're prone to fits of insanity, during these bouts, your exertion of your will is strikingly different from your normal self. As a result, you gain these benefits:

• When you add your charisma modifier to a roll or roll a charisma save, you may instead subtract your charisma modifier from your roll in place of where you would add it. You may perform this feature a number of times equal to your proficiency bonus per long rest.