Base Class: Barbarian
It's an angry water boy.
Crashing Waves
At level 3 you gain the ability to summon the oceans wrath in the form of crashing waves.
While raging, as an action you can summon a powerful wave to draw your enemies close or push them away. A target creature within 20ft must make a contested Strength check against yours. If they lose they are moved 5ft away or towards you. If the fail and the difference in result is greater than 5, they are moved 10ft instead.
If this ability draws a creature into your attack range you can make an attack as a bonus action.
Ocean's Wrath
At level 6 the water no longer hinders your ability to fight. You gain a swim speed of 30ft and can breathe underwater. In addition, melee attacks made while in water are no longer made at disadvantage.
Ocean's Avatar
At level 10 you may expand one of your rage uses to cast the Control Water spell without expanding a spell slot or needing the components.
Whirlpool
At 14th level you can create a whirlpool centered on yourself while withdrawing into your shell. All creatures within a 20ft radius must make a contested Strength check against you. If they fail, they are dragged to within 5ft of you (or as near as possible) and take 4d6 bludgeoning damage. If they succeed they are only dragged 5ft closer and don't take the damage. Allied creatures have advantage on the check. You may do this once per long or short rest.