Legalistic

Your word is your bond. You gain the following benefits.

• Increase your Charisma score by 1, to a maximum of 20.
• You have advantage on discerning loopholes when making bargains.
• Oathkeeper. Once per long rest, you gain advantage on one ability check, attack roll, or saving throw of your choice while trying to fulfill a promise made to another individual.
• Dealbreaker. Once per long rest, select a creature that violated its freely given word to you. For 1 hour, you deal bonus damage to that creature equal to your Charisma modifier.

However, you also gain the following drawback. Whenever you break your word (either purposefully or unintentionally), you must make a DC 10 Wisdom saving throw or be poisoned for 1 minute. This effect is removed if you complete your end of the bargain.