Eldritch Maul.
You can empower the tattoo for 1 minute. For the duration, each of your melee attacks with a weapon or an unarmed strike can reach a target up to 15 feet away from you, as inky tendrils launch toward the target. In addition, your melee attacks deal an extra 1d6 force damage on a hit. Once used, this bonus action can’t be used again until the next dawn.
This finely detailed belt is made of dragonhide. While wearing it, you gain a bonus +3 to the saving throw DCs of your ki features. In addition, you can use an action to regain ki points equal to a roll of your Martial Arts die (1D8). You can’t use this action again until the next dawn.