Monks of the Way of the Deep follow old and forgotten knowledge to augment and refine their abilities with eldritch transformations. Following the Way of the Deep may garner distrust from the common folk, however it is not uncommon for practitioners of such a craft to work for common interests as well. Sometimes the members of a Deep coven may be family members, sharing knowledge and power through blood relations. Other followers may be worshipers of ancient entities, looking to defend themselves and practice their faith in a more hands-on approach. Regardless of this, monasteries of the Deep are few and far between, and are generally slow to trust outsiders.

Bonus Proficiencies

When you choose this tradition at 3rd level, you gain proficiency in the Arcana and Religion skills if you don’t already have them. As you devote your knowledge to otherworldly beings and gods, you have an intricate understanding of such things and can recall such knowledge at your discretion. You also learn Deep Speech if you don't already know it.

Talons of the Deep

Starting when you choose this tradition at 3rd level, you can use writhing tentacles in place of your arms to strike at enemies. The appendage can be used to grab objects and ledges up to 10 feet away without moving. You gain a new attack option that you can use with the Attack action. This special attack is a ranged attack with a range of 15 feet. You are proficient with it, and you add your Dexterity modifier to its attack and damage rolls. Its damage is necrotic, and its damage die is a d4. This die changes as you gain monk levels, as shown in Martial Arts column of the Monk table.

When you take the Attack action and make this special attack as part of it, you can spend 1 ki point to make the special attack twice as a bonus action. When you gain the Extra Attack feature, this special attack can be used for any of the attacks you make as part of the Attack action.

Eldritch Grasp

At 6th level, you gain the ability to sacrifice your mobility to restrain enemies at range. As an action, you can transform your legs into tentacles and sink them into the ground, targeting an enemy standing on the ground. The target must make a strength saving throw or become grappled for up to a minute. You may target more than 1 creature, costing 1 ki per additional target. You may target a number of creatures equal to your wisdom modifier (minimum 1). The target may make a strength saving throw at the end of each of its turns to escape the effect. Large creatures have advantage saving throws from this ability, and larger creatures are unaffected.

While using this ability, your speed becomes 0, you can't benefit from any bonus to your speed. You can end the effect as a free action on any of your turns. You may use this feature once per short rest.

Unfathomable Precense

At 11th level, you can pierce into the mind of a creature held by your will. As an action, you may spend 3 ki points to target one creature held under the effects of Eldritch Grasp. This creature must make a Wisdom saving throw or become charmed for 1 hour. You choose whether a creature charmed in this way is released from Eldritch Grasp. Once the effect ends, the creature knows it was charmed by you. You may use this feature once per long rest.

Deep One Mastery

By 17th level, you have mastery over the occult nature of your powers. You gain the following effects:

• When you strike an enemy with Talons of the Deep, you can choose to deal necrotic, psychic or lightning damage, and its range is increased to 30 feet. Additionally, you can now grab objects and ledges up to 20 feet away using the appendage.
• When a creature is grappled by your Eldritch Grasp, you can use a bonus action to restrain that creature instead.
• You no longer need to breathe, gaining no negative effects from suffocation or lack of air.