Through intense study and constant training, students of the Way of the Chain Master are experts at engaging foes with dual weapons attached to chains known as  kusari.  Chain Master kusari are specially made for each individual, shortly after birth.  During the Ki assisted creation of these weapon chains, blood from the newly born monk is added into the alchemical  process allowing a supernatural bonding  between the flesh of the monk and the kusari on a metaphysical level.  With practice monks of the Way of the Chain Master are able to use Ki to further manipulate their kusari in ways that go above and beyond natural physics and momentum.

Amalgamation of Chains

Starting when you choose this tradition at 3rd level, the latent blood and Ki infused in the kusari bonds and grafts the chains around each of the monk's forearms up to the elbow.  The kusari become an almost supernatural extension of the monk's body and can be attached to any monk weapon.

Gain the following benefits:

• You can spend an hour to attach any monk weapon with the "light" property to the end of the kusari.  Weapons attached in this way gain the 
  "reach" property.
• When you use the Attack action with an unarmed strike, chained strike, or a monk weapon on your turn, you can make one unarmed strike or chained strike as a bonus action.
• Falling Iron:  As part of your attack action you may choose to spend 1-3 Ki points to add 1 martial arts die of damage per Ki point spent, as you violently slam down both weapons into your target.
• Flurry of Chains:  Immediately after you take the attack action on your turn, you can spend 1 Ki point to make two strikes with your chained weapons as a bonus action.
• Intimidating Kata:  you gain the ability to, once per short rest, unsettle or terrify those around you as an action, by spinning and rattling your kusari in a practiced and skillful routine. When you take this action, each creature within 30 feet of you that can see you must succeed on a Wisdom saving throw (DC 8 + Wisdom modifier + Monk level) or be frightened of you until the end of your next turn.

Harmony of Chains

You are more practiced with the use and nature of your kusari, starting at 6th level you gain the following benefits:

• Ki-empowered kusari:  your chained strikes count as magical for the purpose of overcoming resistance and immunity to nonmagical attacks and damage.
• Swinging Attack: the Way of the Chain Master Monk can, as an action, wrap the end of their kusari around an overhead object and swing at any target within 10 feet with an attack bonus equal to their dexterity modifier.  On a successful hit the target takes 3d6 damage (3d8 at level 11, 5d8 at level 17) and if they are large or smaller, make a strength/dexterity saving throw or be knocked prone.  The monk ends the attack in any unoccupied square adjacent to the target.  This does not provoke attacks of opportunity.

Union of Chains

Through practice, use, and meditation you have become one with your kusari.  Starting at 11th level you gain the following benefits:

Cyclonic Chains: You rotate, Kusari extended, in a sweeping twist.  Once per short rest you can use your action to make a chained attack against any number of creatures within 10 feet of you, with a separate attack roll for each target. 

Master of Chains

You have mastered the use of your kusari and have absolute control over these Ki blessed chains.  Starting at level 17 you gain the following benefits:

• Kusari Defense:  Your kusari move almost of their own accord in your defense, intercepting attacks as they happen.  When you are the target of an attack, as a reaction, you can spend 1 Ki point to gain a +5 bonus to AC until the start of your next turn, including from the triggering attack.
• Masterful Lash: with such complete control of your kusari you are also able to strike your targets with the slack in your chains.  Any chained strike made with an attack action deals an additional 1d6 slashing damage.