Way of the Wave Dancer

Monks who follow the Way of the Wave Dancer study the grace, flexibility and power of water, learning to flow like it through the ever changing river of life. They master techniques that allow them to extend their ki into water, wield it like an extension of their own body, with both terrifying efficiency and graceful beauty on the battlefield. 

These monks are usually found along coastal cities, as pirates and sailors, alongside druids that harness the tides and warlocks with dealings to ancient krakens, bending the waves around them and carrying water with them to never be found without their most precious allies.

Dancing Tide

Beginning when you choose this way at 3rd level, you gain a permanent connection to the waters. You learn the Shape Water cantrip if you don’t know it already, and Wisdom is Wisdom is your spellcasting ability for this spell. 

Additionally, you gain a swimming speed equal to your walking speed, and whenever you make a check related to moving swiftly through water or interact gracefully with it, you do so with advantage.

Ki Blessed Wave

Also at 3rd level, you learn to extend your ki into water and use it as an extension of yourself. As a bonus action, you may expend 1 ki point and tie yourself to a body of water within 60 feet of you (it doesn’t have to be naturally occurring, you may carry water with you), animating it: it now counts as a Medium Elemental.

Once per turn, you can mentally command the Ki Blessed Wave to move up a number of feet equal to your walking speed in any direction (no action required). Whenever you make an unarmed strike, you may instead make it from the water’s position rather than yours, and the water can occupy your space. When occupying your space, you can breathe underwater and the range for your unarmed strikes is increased by 5 feet. 

When you make an unarmed strike enhanced by the Ki Blessed Wave or from its position, you may use your Wisdom modifier for attack and damage rolls, and you may choose for the attack to deal slashing or cold damage, rather than bludgeoning. 

Additionally, the first time each creature is damaged this way each turn, the creature takes additional cold damage equal to one roll of your Martial Arts die, and you may choose one of the following effects to impose on it (choose each time): 

• Its speed is reduced by 10 feet until the end of your next turn.
• It is moved up to 10 feet towards or away from you.
• It must succeed on a Dexterity saving throw against your Ki save DC or be knocked prone.

The Ki Blessed Wave lasts for 10 minutes, and if it is ever more than 60 feet away from you at the end of your turn, it is instantly recalled to your space. Ki Blessed Wave cannot be manipulated or controlled by a creature besides you, it can enter a hostile creature's space and stop there, it can move through a space as narrow as 1 inch wide without squeezing, and if it is subjected to an environment that would instantly evaporate it, it does so normally. You can only have one Ki Blessed Wave at a time.  

Water Flourish Techniques

Starting at 6th level, you learn the following techniques to perform thanks to your connection to water and the flowing ki in it.

• Crashing Wave: After you hit with an unarmed strike, you may expend 1 ki point to cause the attack to push the creature 15 feet in any direction, infusing it with the power of waves. If it is pushed into an object this way, a creature takes additional bludgeoning damage equal to one roll of your Martial Arts die. 
• Oceanic Defense: As a reaction to being hit by an attack, you may expend 2 ki points to move up to half your movement without provoking opportunity attacks, as you temporarily turn into water.
• Shifting Form: On your turn, you can move through any space that is at least 1 inch in diameter and do so without squeezing. When you stop moving, the regular squeezing rules apply if you’re in a space one size smaller than you. You can’t willingly stop in a space smaller than that, and if you’re forced to do so, you immediately flow to the nearest space that can fit you, back along the path of your movement.

Tide Bending

At 11th level, you have learnt to command an even greater amount of water with your Ki. When you animate your Ki Blessed Wave, you may instead make it a Large Elemental instead of a Medium one. While your Ki Blessed Wave is Large or bigger, you gain the following benefits:

• As long as it occupies your space, you gain a bonus to your walking and swimming speed equal to your Unarmored Movement bonus, and a flying speed equal to half your walking speed.
• As long as it isn’t occupying your space, you can use an Action to try and submerge a creature within 5 feet of it into its shifting watery form. It must succeed on a Strength saving throw against your Ki save DC. On a failure, a target takes cold damage equal to three rolls of your Martial Arts die + your Wisdom modifier and becomes  restrained unless it uses its action to make a Strength check against your Ki save DC to try and escape. A creature restrained this way can still be attacked by your Ki Blessed Wave.
• The first time you and the water occupy the same space each short rest, you gain temporary hit points equal to your Monk level + your Wisdom modifier.

Flowing Tsunami

By the time you’ve reached 17th level, your power over water becomes uncanny and almost mythical. When you animate your Ki Blessed Wave, you may instead make it a Huge Elemental, instead of a Medium or Large one. While your Ki Blessed Wave is Huge, as long as it isn’t occupying your space, you can use an Action to turn the Ki Blessed Wave into a tsunami.

The Ki Blessed Wave transforms into a 50 foot long, 10 feet wide and 15 feet tall wall of water. At the start of your turn while the wall lasts, it moves 10 feet forwards. Each creature in the area when it first appears or moves, or any creature that enters the area for the first time on a turn, must make a Strength saving throw against your Ki save DC. On a failure, they take bludgeoning damage equal to seven rolls of your Martial Arts die + your Wisdom modifier and are caught by it, taking half as much damage and suffering no other effects.

A creature caught in the wall can move by swimming. Because of the force of the wave, though, the creature must make a successful Strength (Athletics) check against your Ki save DC in order to move at all. If it fails the check, it can’t move. A creature that moves out of the area falls to the ground.

Once you use this feature, you can't do so again until you finish a long rest, unless you spend 8 ki points to use it again.