Those who follow the way of the ki blade can manifest their ki as a weapon made of energy.

Ki Blade

At 3rd level, you gain the ability to manifest a blade forged out of your own ki. Over the course of a long rest, you create a ki blade in your empty hand. The ki blade is a two-handed monk weapon. You choose it's damage type when you manifest it. The damage die of your ki blade is one die higher than your martial arts die. For example, if your martial arts die is a d8, your ki blade damage is a d10. You are proficient with it while you wield it. When a Monk feature would allow you to make an unarmed strike, you can attack with your ki blade instead. 

This weapon counts as magical for the purpose of overcoming resistance and immunity to nonmagical attacks and damage. Your ki blade reappears at your side if it is more than 5 feet away from you for 1 minute or more. Your ki blade disappears if you die or if you are knocked unconscious by a critical hit while wielding it. You can only use this feature again if your ki blade is destroyed.

Ki Slash

At 6th level, you gain the ability to project your ki blade into a ranged attack.

When you attack with your ki blade, you can target a creature within 60 feet of you. If you hit with the attack, that creature takes the damage from your ki blade. You can increase the damage dealt by this attack by expending ki points. For each ki point you spend, the damage increases by one dice. For example, if your attack would deal 1d6 damage, but you spend 3 ki points, it instead deals 4d6 damage. The amount of ki you can spend on this feature is equal to half your level rounded up.

You can use this feature an amount of times equal to your Wisdom modifier. Once you do, you cannot use this feature again until you finish a long rest. Once you reach 11th level, you are no longer limited in your uses of your ki slash, nor the amount of your ki you can expend.

Sword Eater

At 6th level, you can perform a ritual to absorb the power of a magical weapon. You can spend 1 hour to perform the sword eating ritual on a magic weapon. You must be in contact with the weapon throughout the ritual. The ritual fails if the weapon is an artifact, sentient, or if it requires attunement and you are not attuned to it. Once the ritual is complete, the weapon is destroyed and your ki blade gains the magic properties of that weapon.

If the magic properties of the weapon overlap with that of a weapon previously subjected to the sword eating ritual, your ki blade takes the stronger property. For example, if you perform the ritual on a +1 longsword, then a +2 mace, your ki blade would keep the properties of the +2 mace.

Once you perform the sword eating ritual, you cannot do so again until you finish a long rest.

One with the Blade

At 11th level, the bond between you and your ki blade becomes even stronger. When a Monk feature would apply to an unarmed strike, you can apply it to your ki blade attack or ki slash instead.

Blade Form

At 17th level, your mastery of your ki blade allows you to temporarily enter a different form. As a bonus action, you can spend 6 ki points to enter the blade form. Blade form lasts for 1 minute. While in blade form:

• Your ki blade deals an additional die of damage.
• Attacks with your ki blade bypass resistance to it's damage type, and a creature immune to it's damage type takes half damage instead.
• When a creature hits you with an attack while in blade form, you can use your reaction to make an attack against that creature using your ki blade.

Once you use your blade form, you cannot do so again until you finish a long rest.