From a monastery in the frozen climates, they have learned to adapt to and emulate/channel their extreme environment. One will often find such monks honoring the goddess Auril. This doesn't necessarily mean they are evil. But Auril's territory are the cold climates and many who live in such places will honor the Frost maiden as a matter of survival.

3rd Level - Ice Body

You’ve trained your body to adapt to bitter climates:

• You are immune to exhaustion caused by natural cold environments.

• You have advantage on saving throws against supernaturally cold environments (such as magical blizzards or spells like Cone of Cold).

• You also have advantage on saving throws against natural heat, but not against magical heat effects.

Additionally, you can channel your inner chill into your strikes:

Icy Strikes: Once per turn, when you hit a creature with an unarmed strike, you can force them to make a Constitution saving throw (DC = 8 + your proficiency bonus + your Wisdom modifier). On a failure, the creature has disadvantage on the next weapon attack or Strength check it makes before the start of your next turn, as numbing frost bites into their muscles.

6th Level - Frost

 

Your connection to cold strengthens both your strikes and your movement.

• Frozen Fist: Your unarmed strikes deal an additional 1d4 cold damage. This increases to 1d6 at 11th level and 1d8 at 17th level.

• Slippery Grace: You can move across ice or slippery surfaces without needing to make checks or risk falling.

• Trail of Ice: When you move, you may leave behind a 5 ft wide trail of magical ice that lasts until the start of your next turn. This area is considered difficult terrain for other creatures. You can suppress this effect at will.

• Aura of Winter (3 Ki): As an action, you radiate freezing energy in a 10-foot radius for 1 minute (concentration). While active:

  • Enemies that start their turn within the aura must make a Constitution saving throw or have their speed halved and suffer disadvantage on Strength and Dexterity checks, saving throws, and attack rolls until the start of their next turn.

  • Creatures may repeat the saving throw at the end of their turn.

  • Nonmagical flames within the aura are extinguished.

  • You gain resistance to fire damage.

 

11th Level - Hoarfrost

 

You unleash a wave of ice that debilitates your enemies.

You can stomp the ground and release a wave of freezing energy. As an action, you may spend 2 ki points to create a slick cone of ice in a 25-foot cone.
Each creature in the area must make a Dexterity saving throw or fall prone. They must also make a Constitution saving throw, taking 2d6 cold damage on a failure (half on a success).
The area becomes difficult terrain for all creatures except you until the start of your next turn.

17th Level - Rime

 

You have become a living storm of winter, channeling cold through movement and focus rather than incantation.

• Frozen Pulse (6 Ki):
  As an action, you release a devastating wave of cold in a 60-foot cone. All creatures in the area must make a Constitution saving throw (DC = 8 + your proficiency bonus + your Wisdom modifier). On a failed save, a creature takes 8d8 cold damage and is slowed until the end of your next turn (their speed is halved, they take -2 to AC and Dex saves, and can’t use reactions). On a successful save, they take half damage and are not slowed.
  Any nonmagical flame in the area is extinguished. This ice lingers, turning the area into difficult terrain for 1 minute.

• Winter's Mantle (7 Ki, Bonus Action):
  You surround yourself in an aura of living ice for 1 minute (no concentration). While this aura is active:

  • You gain resistance to fire damage and immunity to cold damage.

  • Your unarmed strikes deal an additional 1d8 cold damage, and creatures hit by them must succeed on a Strength saving throw or have their speed reduced to 0 until the start of their next turn.

  • As a reaction to being hit by a melee attack, you can deal cold damage equal to your Wisdom modifier + your monk level, and the attacker must succeed on a Constitution save or suffer disadvantage on their next attack roll.