Way of the Frozen Lotus Flower

The Frozen Lotus Flower is the symbol, namesake and holy relic of the Frozen Lotus monastic order. They harness the flow of the elements to infuse their martial arts with ice by manipulating the element of air and water, although they possess some control of the other elements the combination creating ice is their speciality. 

Frostbitten

Ki Spellcasting: you gain access to a pre selected list of Ki Spells which you can cast spells at the cost of 1ki per spell level and obeying all other rules for Spellcasting, your Spellcasting ability is Wisdom, DC and to hit are calculated as any other Spellcasting class,

Absorb Elements, Armor of Agathys, Chromatic Orb and Ice Knife.

Additionally you gain Ray of Frost cantrip which can be used with flurry of blows or the bonus action strike granted by martial arts. 

Icefusion

Your strikes become infused with freezing force. Your martial arts die is one size larger.

When attacking you can create Monk weapons made from ice, when dealing damage with created ice weapons or the unarmed strike you can choose cold damage in place of the weapons normal damage type.

When you hit with a created ice weapon or unarmed strike you can spend a ki point to make that weapon +1 (this effect lasts 1 min) (at 11th 2 ki +2, at 17th 3 ki +3)

Ki Spells Hold Person, Mirror Image, Misty Step, Pass Without a Trace

Kombo Master

If you hit with 3 attacks you can spend Ki and your reaction to use one of your Ki Spells.

Additionally you can expend Ki to perform multiple reactions starting at a cost of 1 Ki and increasing by 1 each time you do an additional reaction until you complete a long rest.

Ki Spells Elemental Weapon, Sleet Storm, Slow

Fatality

You can sense when enimies are Bloodied (50% HP) if you land 3 or more strikes and an opponent is bloodied you can spend 3 ki to force a Con Save and kill a humanoid by freezing all the air and water in their bodies leaving behind an ice statue, if the target is not a humanoid you can instead expell frozen air and water from their bodies inflicting a 10d10 wound.

Your level 1 Ki Spells are free to cast at base level and you can flurry of blows after casting or bonus strike granted by martial arts. 

Ki Spells Elemental Bane, Stoneskin, Cone of Cold, Steel Wind Strike

The level 5 Ki Spells can only be cast once per long rest each.