As your Monastic Tradition you learn the way of the Frozen Fist, at "The Monastary of Auril" the goddess of winter.

Fist of Frozen Fury

Starting at level 3 on a constitution saving throw (DC 8 + your Constitution modifier) on fail their speed is halved, on a success their speed stays the same. (At level 10 their speed is reduced 0)

Memory in Ice

Water contains memory now, all you must do, is freeze it to remember. (you gain proficiency with investigation checks, and you gain proficiency with insight.)

Level 6: Frozen Reflection

As a reaction, you can use 2 KI points, to cause your opponent to roll a constitution saving throw. (DC 8 + your constitution modifier) on success the opponent take 1d6 cold damage halved and their movement speed is halved and you still take the damage. on a fail, the opponents movement speed is reduced to 0, and cannot take reactions until your next turn, you still take the damage.

Exportation of the Soul

Starting at level 11 you can use up 1 KI point to create a circle of freezing wind around you, that deals 1d6 cold damage to both you and the opposing creature, if the creature ends their turn in the five foot circle, or if you end your turn and there are opponents in the circle.

At level 15 it no longer does damage to you.

Frost Walking

Instead of Swimming you can instead walk on the water that freezes beneath your feat in a 10 foot radius around you.

Imbuement of the Soul

Starting at level 17, all unarmed strikes now strikes now cause the opponent to roll constitution saving throws (DC 8 + your constitution modifier) on a fail the opponents, have their movement is halved,  and they cannot take reactions against you or your allies. You resist all cold damage.