Based on the concept of Sub-Zero, and all characters bearing the name. Characters named and likeness are all owned by Netherrealm Studios.

A clan forged in absolute temperatures, the Lin-Kuei fight to defend the realm from dangers both mortal and extraplanar. This noble clan had been corrupted from within,  but has since been reformed to their rightful glory by a new Grandmaster. 

Through careful training and discipline, members of the Lin-Kuei have learned to harness their inner power into the ancient art of cryomancy, the manipulation of ice, even being able to produce burning colds from their very bodies.

Cryomancy

Beginning at 3rd level you are able to harness your Ki to awaken your latent cryomancer abilities. You know the cantrips Frostbite, Shape Water, and Ray of Frost. You also learn Chromatic Orb and Ice Knife at 3rd, Snilloc's Snowball Swarm at 5th, Sleet Storm at 9th, Ice Storm at 13th, and finally Cone of Cold at 17th . 

By spending Ki points equal to the level of the spell +1 you can cast the spells above without a spell slot. To cast spells at higher levels you may spend additional Ki points to meet the cost, but cannot cast spells over 5th level.

Lin-Kuei Arsenal

Also at 3rd level you are able to create a weapon out of pure, hardened ice that you can summon at will. The weapon must be a Monk Weapon (As detailed in the Monk class guide) and requires 4 hours of study and meditation. To change this weapon requires half your current Ki points (minimum of 1. Cannot be done if  only 1 Ki point is had) and 4 hours of meditation. This weapon appears when ever you call it and the ice appears to grow out of your hand. The weapon does not cost an action to summon.

The weapon has the same statistics as the weapon it's based on. In addition to its normal damage, the weapon created through this process also deals the damage of your Martial Arts die in Cold damage.

Tundra's Resolve

Upon reaching 6th level, you now learn to harness your Ki to unlock feats that set the Lin-Kuei apart from the rest of the world. At 6th level you are now resistant to Cold damage. You also treat icy surfaces as normal terrain and can move twice as fast (moving 10ft. costs only 5ft. of movement) during your movement when you are standing on ice.

Additionally, you are able to turn the ground around you thin ice. As an action, you can spend 3 Ki Points to create a ring of ice in a 10ft. diameter of your position You can use this ability once per Long Rest.

Grandmaster's Guard

At 11th level the Grandmaster of the Lin-Kuei teaches you how to better defend yourself in kombat against difficult adversaries. Whenever a creature declares an attack on you, you can use your reaction to spend 3 Ki points and shield yourself with ice. Doing so raises your AC by your WISDOM modifier and lasts till the beginning of your next turn. This ability has uses equal to your Wisdom modifier per day (minimum 1).

Legendary Ice Klone

A legend among your clan teaches you the most advanced technique, the art of the Ice Klone. At 17th level, as a bonus action, you may summon an ice golem of your likeness to a space within 5ft. of you. The Klone has 1/4 your current health and its AC is equal to yours when summoned and it is immune to being charmed or frightened. The Klone cannot make any actions, and is treated as an obstacle. The Klone thaws away after your WISDOM modifier turns. If a Klone is destroyed, any creature within a 5ft. radius must make a Dexterity saving throw vs. your Ki DC. If the creature(s) fails, they take 2d8 Cold damage or half as much on success. You may pick 1 of the Klone Maneuvers below to learn. You may learn an additional Klone Maneuvers on your own, but to do so recquires 36 hours of study and practice (Maximum of 2). You may only have one Klone active at a time.

 

Klone Maneuvers

The maneuvers are ordered alphabetically.

Klone Armor. As a bonus action, if you are within 5 ft. of your Klone, you can spend 5 Ki points to encase your body within it. Doing so makes your AC 21, changes your unarmed strikes to deal Cold damage, but reduces your movement speed by half. After every turn, you must make a Constitution Save or drop the Klone. This effect lasts for 3 turns unless the check is failed or if the Klone thaws.

Klone Extension. As a bonus action you can spend 4 Ki points to summon your clone 5ft. in front of you. The Klone mimics your movements and allows you to make unarmed strikes you normally be able to make. (The range of unarmed strikes increase to 10ft.)

Klone Slide. You can spend 4 Ki points and your action to send your Klone sliding in a straight line. The range of the slide is 15ft. and the target must make a Dexterity save vs Ki Save. If the target fails they take 4d8 cold damage and are frozen until the beginning of your next turn or they can spend an action to break free which require a strength check vs your Ki Save DC, or if they succeed they instead take half as much and are knocked prone.

Klone Teleport. Once per turn as a bonus action, If your Klone is within your full movement of you, you may spend 3 Ki points to trade locations with your Ice Klone. You can use this ability 2 times per Short Rest.