Crown of the Oathbreaker © 2022, Elderbrain, Inc.; Authors: Gabor Dan, David Feher, and Tamas Marton

A few rare monks participate in unarmed combat practices that emulate the fighting techniques of their foul aberrant masters. They are trained in ancient monk traditions that eventually enable them to turn their limbs into tentacles, giving them combat superiority.

Tentacle Limb.

Starting at 3rd level, you can turn your body into the form of an aberrant creature. As a bonus action, you can spend 1 ki point to transform your arm into a 10-foot long tentacle for 1 minute. The tentacle has reach and can be used as part of an unarmed strike. The tentacle deals bludgeoning damage equal to your Martial Arts die + your Strength or Dexterity modifier. You gain advantage on Strength (Athletics) skill checks to grapple an opponent with the tentacle. At 11th level, you can transform both of your arms into tentacle limbs.

Nerve-wracking Strike.

Starting at 6th level, you can channel psychic energies into your tentacle strikes. Your unarmed strikes with your tentacle limb count as magical for the purpose of overcoming resistance and immunity to nonmagical attacks and damage. You can spend 1 ki point to deal additional psychic damage with one unarmed strike of your tentacle limb equal to one roll of your Martial Arts die + your Wisdom modifier.

Psychic Barrage.

Starting at 11th level, your ability to channel harmful psychic powers intensifies. When you use Flurry of Blows after an attack made with Nerve-wracking Strike, you can replace each of the unarmed strikes with a use of your Nerve-wracking Strike without spending additional ki points.

Suffocating Strike.

Starting at 17th level, you learn how to force your tentacle limb into the throat of your enemies to kill them. The reach of your tentacle limb becomes 15 feet. As an action, you can attempt to grapple your opponent with your tentacle limb. A successfully grappled target becomes unable to speak and if you choose, it starts to suffocate while being grappled by you.