You've been granted a mysterious power, and among your monastic training have learned to harness and control it. This power appears on a person's body as a glowing tattoo, spreading from their torso to one of their arms. While the exact origin of this ability is unknown, what is known is there can only be six people with such an ability at any given time, and this ability is passed down from one person to another upon the wielder's death. 

Using this power, one can use ki to summon astral arms to their aid to assist them in combat.

Phase Ability

At 3rd level, you may choose one of three abilities: Phase Slam, Phase Lock, and Phase Cast. You may also choose an element: Fire, Acid, or Electricity. Any abilities you choose will deal damage of your chosen element. 

Phase Slam

You may spend 2 ki points to jump into the air, summoning astral arms in a circle around you as you do. Choose a space 10ft from you to land, slamming your fists into the ground dealing 2d6 of your chosen element's damage to enemies in a 5ft area. At 6th level, you may use ki points to increase the distance you jump (1 ki per 5ft, to a max of 4), and the damage dealt increases [3d6 at 6th, 4d6 at 11th]

Phase Lock

You may spend 2 ki points to summon an astral arm under an enemy up to 30 ft away, forcing them to make a Strength saving throw (DC 8+Wisdom+Proficency). On a failed save, they are grabbed by the hand, taking 2d6 of your chosen element's damage and becoming restrained for the ability's duration. The hand stays summoned for 1 minute, or if the user's concentration is lost. At 6th level, you can use an additional ki point after a target has been grabbed to summon another hand, slamming into the restrained target for an additional 2d6 damage and ending the ability's effects. At 11th level, damage dealt increases to 3d6 for both the initial grab and additional slam attack.

Phase Cast

You may spend 2 ki points to create an astral projection of yourself and fire it forward in a 30ft line, 10ft across. This deals 2d6 damage of your chosen element to each enemy hit. At 6th level, you may spend an additional ki point to have enemies hit to perform a Constitution saving throw (DC 8+Wisdom+Proficency) or be stunned for a turn. Damage increases as you level as well [3d6 at 6th, 4d6 at 11th]

Phase Strengthening

At 6th level, as a bonus action, you may use 1 ki point to empower your strikes with your chosen element, making your attacks deal an additional 1d6 of that element's damage and lasting for 2 turns.

Helping Hands

At 11th level, as a bonus action, you may use 2 ki points to summon six astral arms to your sides to assist you in combat, choosing one of the following effects. This lasts for 3 turns.

• The arms defend you from projectiles and other ranged attacks, giving you a +5 reduction to damage taken when using deflect missiles, and a +3 to your AC against ranged spells directed at you (this doesn't affect AOE effects such as fireball or cone of cold). 
• The arms defend you from other melee attackers, increasing your AC by +3 against melee attacks directed at you.
• The arms assist you in attacking your foes, dealing an extra 1d6 of your damage element to each attack you make. 

Phase Guardian

At 17th level, when you would be reduced to 0 hit points, you may use all of your remaining ki points to be brought back to your feet. You regain health equal to 8 per ki point used. This can only be used once a day (resetting after a long rest), and only works if you have a least 1 ki point remaining.