Way of Kenshi Monk Subclass

Level 3:

Blindsight - You're immune to the Blinded condition.

Devil's Sight - You can see up to 24m in both magical and natural darkness.

Summon Sento - Expend a bonus action and a ki-point to summon a magical katana until your next long rest. Sento is a versatile, finesse katana that does 1d8(1d10 versatile) psychic damage. Refer to the images, or see below for a detailed scaling description.

Longsword Proficiency

Level 6:

Minor Telekinesis - Expend a bonus action and a ki-point to attempt to throw a target or object within 5m.

See Invisibility - You can see invisible creatures.

Level 10:

Telekinesis - You can cast the Telekinesis spell once per long rest. When cast in this way, the spell doesn't require concentration.

Sento Scaling:

Level 3:

+1 to Attack and Damage Rolls

Life Transference Passive - When you reduce an enemy to zero hit points with Sento, you regain hit points equal to one roll of your martial arts die plus your wisdom modifier.

Edge of Darkness Weapon Action - Create a cloud of magical darkness while you attack.

Level 6:

All features from Level 3

+2 to Attack and Damage Rolls

Reflective Shell - When you reduce an enemy to zero hit points with Sento, a reflective shell envelops you for two turns, reflecting any projectiles targeted at you back to their point of origin. This effect an stack. (You make the attack roll with disadvantage using the attacker's stats, so it will rarely hit. This is how it's coded in the game, and I don't plan on changing it since this is meant to be more defensive than offensive.)

Soulbreaker Weapon Action - Rend the enemy's body and soul, and possibly Stun them for two turns.

Level 10:

All features from Levels 3 and 6

+3 to Attack and Damage Rolls

Summon Ancestral Blade - When you reduce an enemy to zero hit points, you automatically summon your Ancestral Blade from their corpse. You can control the blade telekinetically on its turn. The blade lasts for 10 turns and can only be summoned once per combat. This is functionally similar to Spiritual Weapon except the blade uses its own stats and does psychic damage. It can also move or fly up to 15m.

Perfectly Balanced Strike Weapon Action - You can use your bonus action to make an additional attack with Sento.