Boon of the Deep

“The sea gives. The sea takes. And sometimes… it leaves a mark.”

You bear a mysterious glowing mark gifted (or cursed) upon you during a failed ritual within one of the Vaults Beneath the Tide. The power flows through you in strange tides—sometimes surging, sometimes silent—but always there, deep beneath the surface.

Deep Charges

You gain a number of Deep Charges equal to your proficiency bonus. You regain all expended Deep Charges after a Long Rest.You can also regain 1 Deep Charge whenever you:

• Land a critical hit,
• End a turn on 1 hit point,
• Or succeed on a saving throw against a charm or fear effect (the sea does not yield).

Deepmark Powers

You can expend Deep Charges to fuel special abilities tied to your boon.

Riptide Shot (1 Charge)

(Reaction)
When you get hit with a ranged attack, you fire a concussive shot imbued with abyssal pressure. Target is pushed 15 feet away and must make a Strength save (DC = 8 + Prof + INT) or be knocked prone. If used underwater, push becomes 30 feet, no save.

Abyssal Sight (1 Charge)

(Action)
For 10 minutes, you can see perfectly in darkness (magical and non-magical) up to 120 ft and can see through murky water, fog, or smoke as if it were clear air.
You also gain advantage on Perception (sight-based) checks for the duration. While active, your eyes glow faint blue, like deep water.

Whispers from the Trench (2 Charges)

(Action)
You open your mind to the presence in the deep. You can cast Detect Thoughts or Augury (your choice). If you choose Augury, the result may come in eerie, oceanic metaphors (“The current flows clear” = Weal, “The trench awakens” = Woe, etc.).

Undertow (2 Charges)

(Bonus Action)
You can use your bonus action to teleport up to 60 feet to a space you can see. You leave a deep puddle of water behind in the space you previously occupied, making it difficult terrain.

Tidal Echo (2 Charges — Prerequisite: 9th level)

(Reaction)
When you’re hit by an attack, you can use your reaction to dissolve into a splash of water, teleport up to 30 feet, and reappear with a mirror of yourself made from seawater.

• The echo lasts 1 minute or until destroyed (AC 13, 1 HP, immune to poison/psychic).
• On your next turn, you can use your bonus action to swap places with the echo or make a ranged attack from the echo's position.

(Extend an additional Deep Charge: Enemies that destroy the echo must make a WIS save or suffer disadvantage on attacks against you until your next turn.)

Voice of the Abyss (4 Charges — Prerequisite: 14th level)

(Reaction)
You channel the full presence of the deep entity that marked you. For 1 minute:

• Your voice reverberates with layered, alien tones.
• You gain telepathy within 60 feet.
• As an action, you can issue a command in Deep Speech to one creature you can see within 60 ft. It must succeed on a Wisdom saving throw (DC 8 + Prof + INT) or be Charmed until the end of your next turn.

If the creature is already charmed or frightened by you, they instead become Stunned for 1 round on a failed save.

Depth Surge (5 Charges — Prerequisite: 17th level)

(Action)
You are able to channel the strength of the Deep. Once per long rest, you can use your action to unleash a catastrophic surge of power from the trench beyond reality.

Choose one of the following effects:

• Tempest Maw — A massive spectral sea-creature’s maw erupts in a 30-ft cone in front of you. Each creature in the area must make a DEX save or take 8d10 force damage and be pulled 15 feet toward you. On a success, half damage and no pull.

• Tidal Wave — You slam your mark into the ground. A 60-ft radius water sphere pulses outward. Flying creatures are knocked prone unless they pass a STR save (DC 8 + Prof + INT). All enemies must succeed on a CON save (DC 8 + Prof + INT) or be Blinded and Deafened for 1 minute. While under the effect, enemies repeat their saving throw at the end of their turn.

• Shield of the Deep — You summon a storm sphere of churning water and pressure in a 20-foot radius centered on you. Lasts 1 minute. Hostile creatures treat the area as difficult terrain and take 2d8 cold + 4d8 bludgeoning when entering or starting their turn inside.