Moisture Mastery
You've learned the principal innate to Fishmen Karate, moisture exists everywhere even in the air. You gain the Cold affinity if you do not already have it. Your unarmed and Brawler Weapon attacks can originate from anywhere within 10 ft of you and are treated as if you were in that space for features, feats, and techniques that trigger off being adjacent to you during an attack. Additionally at the start of your turn, you can spend a combo die to extend your Moisture Mastery range even further. Roll the combo die and increase the attacks range by half the rolled amount (rounded up) x 5.
Flowing Water
At 10th level you've studied the ebb and flow of the tides and learned their strengths to attack the water directly inside a creatures body. Once per turn, your unarmed and Brawler weapon attacks may now deal force damage, in addition when they land a critical strike the target creature gains one rank of the Bruised condition. The damage Bonus from Bruised now applies to Force damage that you deal.
Tsunami
Your strikes embody the sea's wrath. At level 14, you can choose between Cold and Force damage whenever you would deal damage through any attack, feature, or technique. Additionally whenever you deal Cold or Force damage you double you damage modifier, if you would not normally add your damage modifier you can do so, but do not double it.
Avatar of the Sea
You become an embodiment of the ocean. Finally at 18th level when you successfully hit a creature with an unarmed or Brawler Weapon attack you can use the moisture surrounding the creature to move them 5ft in a direction of your choice. Additionally you gain +1 to your critical range with unarmed and Brawler Weapon attacks and techniques that use either of these as a component.