AMPHIBIOUS. The priest can breath air and water.
INNATE SPELLCASTING. The priests spellcasting ability is wisdom (spell save DC13,+5 to hit with spell attacks). It can innately cast the following spells, requiring no material components.
At will: Command, Create or Destroy Water
3/day each: Control Water, Darkness, Water Breathing, Water Walk
1\day each: Call Lightning, Evard's Black Tentacles.
THUNDEROUS TOUCH. Melee spell attack: +5 to hit, reach 5ft, one creature. Hit: 27 (5d10) thunder damage.
VOICE OF THE KRAKEN (recharges after a short or long rest). A Kraken speaks through the priest with a thunderous voice audible within 300 ft. Creatures of the priests choice that can hear the Kraken's words (which are spoken in Abyssal, Infernal, or primordial) must succeed on a DC 14 Charisma saving throw or be frightened for a minute. A frightened target can repeat the saving throw at the end of each turn, ending the effect on a success.