Sekolah, The Great Shark

Your pact is with the Shark-Father Sekolah, an evil god that resides in Stygia, the fifth layer of the Nine Hells. Sekolah is known for being the greatest tyrant of the sea, taking pleasure in the hunt, plunder, and inevitable slaughter of his leviathan prey, or any other creature he deems worthy. Sekolah values strength above all else, and requires his followers to prove themselves thoroughly before he grants them his power. Therefore, your pact with him is a brittle one, easily broken if you show any sign of weakness.

Aspect of Sekolah

Prerequisite: Great Shark patron
You develop the following features coined by the Father of Sharks:

• You grow rows of razor-like teeth that can be used as a natural weapon to make a bite attack. On a hit your bite deals 1d4 + your Strength modifier as piercing damage.
• You gain a swimming speed of 30 feet as webs form between your fingers and toes, a dorsal fin spouts from your back, and a muscular tail extends from your tailbone.
• You form gills which allow you to breath both air and water.

Calling from the Depths

Prerequisite: 7th level, Pact of the Tome feature
You can cast secret chest without expending a spell slot, providing material components, or a cumulative chance of ending the spell after 60 days. You can’t do so again until you finish a long rest.

Additionally, you can add the following spells to the list of spells you can cast using your Mystic Arcanum when you reach the level required to cast them. At 13th level you can cast submerge vessel*, at 15th level you can cast tsunami, and at 17th level you can cast selachian whirlwind*.

Devour Pawn (Dominus)

Prerequisite: 10th level, Pact of the Chain feature
You can use your action to devour your pact of the chain familiar, reducing its hit points to 0. When you do, your power grows tremendously, your size doubles in all dimensions, and your weight is multiplied by eight. This growth increases your size by one category - from medium to Large, for example. If there isn't enough room for you to double your size, you attain the maximum possible size in the space available. Until this effect ends, you gain +4 to your Strength ability score (to a maximum of 24) and each creature within 5 feet of you at the start of your turn takes 1d10 force damage. Your weapons also grow to match your new size. While these weapons are enlarged they have the reach property, and attacks you make with them deal one extra weapon damage dice. These effects last for 1 minute. You must finish a long rest before you can use this invocation again.

Ghostwater Dive

Prerequisite: 10th level
You can use your action to gain a burrow speed of 30 feet, a swim speed of 60 feet, and tremorsense out to a range of 30 feet for up to 10 minutes. For the duration, you can burrow through nonmagical, unworked earth and stone, and while doing so, you don't disturb the material you move through. You must concentrate (as if concentrating on a spell) to maintain these effects.

If you occupy the same spot as a solid object or surface when this effect ends, you are immediately shunted to the nearest unoccupied space that you can occupy and take force damage equal to twice the number of feet you are moved.

You must finish a long rest before you can use this invocation again.

Prey Seeker

Prerequisite: eldritch blast cantrip, Great Shark patron
Once per turn, when you miss an attack with your eldritch blast, you can reroll the attack if the target is below its maximum hit points.

Relentless Hunter

Prerequisite: Great Shark patron
You have advantage on any Wisdom (Perception) or Wisdom (Survival) checks you make to hunt or track a creature below its maximum hit points, or that has recently suffered a major injury. Additionally, you can smell the scent of creatures below their maximum hit points from up to a mile away, allowing you to accurately pinpoint the distance and direction to them.

Riptide

Prerequisite: 10th level, Pact of the Blade feature
While wielding your pact weapon, you can use Cull the Meek when a creature provokes an Attack of Opportunity. Furthermore, when you hit a creature with Cull the Meek, it is pulled into an unoccupied space nearest you, takes an additional 1d6 force damage (which adds to your temporary hit point result), and its speed drops to 0 for the rest of the turn.

Biting Blade

cantrip transmutation

• Casting Time: 1 action
• Range: 5 feet
• Components: V, M (a weapon)
• Duration: 1 round
• Classes: Warlock

You channel primal magic into a weapon you're wielding, causing it to animate and twist into a snapping maw. As part of the action used to cast this spell, you must make a melee attack with a weapon against one creature within the spell's range.

On a hit, the target takes 1d8 piercing damage. If the target provokes an attack of opportunity from you before the spell ends, your attack deals 1d8 additional piercing damage as your weapon sinks its teeth in, and its speed is reduced by 10 until the start of your next turn. After you make an opportunity attack, or at the start of your next turn, your weapon returns to normal.

This spell's damage increases when you reach higher levels.

At higher level. At 5th level, the initial attack deals an extra 1d8 piercing damage to the target, and the damage the target takes from the attack of opportunity increases to 2d8. Both damage rolls increase by 1d8 at 11th level and 17th level.

Death From Below

5th level conjuration

• Casting Time: 1 action
• Range: 30 ft.
• Components: V, S, M (a quipper)
• Duration: Instantaneous
• Classes: Warlock

You hurl a quipper at a creature within range. Make a ranged spell attack against the target. This attack always hits if the target is submerged in water. On a hit, the target takes 1d10 piercing damage. Whether your attack hits or not a 15-foot-radius whirlpool appears centered below the target. The water is 10 feet deep and is considered difficult terrain. If the attack hit, the whirlpool remains centered on the target no matter where or how it moves.

At the end of the targets following turn, a gargantuan maw rowed with razor sharp teeth appears and attempts to bite all creatures in the whirlpool's radius. All creatures in the area must make a Dexterity saving throw against your warlock spell save DC to avoid the snapping maw. The target of this spell makes this save with disadvantage if the attack hit. If a a creature fails, it is dragged into the maw and bitten, taking 4d10 piercing damage and 4d10 slashing damage. If this is enough to reduce the target to 0 hit points, you can choose to have them be swallowed whole by the mouth, consuming them and sending their bodies to Stygia. Either way, the maw then immediately disappears.

At Higher Levels. When you cast this spell using a spell slot of 6th level or higher, the piercing damage (from the maw) or the slashing damage (your choice) increases by 1d10 for each slot level above 5th.

Submerge Vessel

7th level transmutation

• Casting Time: 1 minute
• Range: Touch
• Components: V, S, M (a glass marble or piece of soap)
• Duration: Concentration, up to 8 hours
• Classes: Druid, Wizard

When this spell is cast upon a water vehicle, the vessel is surrounded by a protective bubble of constantly replenishing, breathable air and sinks beneath the waves. For the duration of the spell, the vessel can travel beneath the water as easily as it did above. While under the effects of this spell, the vessel has magical propulsion that gives it a maximum speed of 120 feet. The vessel’s pilot uses the normal water vehicle skill to control the ship while under this spell’s effects, and can command it to dive and ascend as part of the vessel’s normal movement.

Despite the magical propulsion, the vessel still requires its crew to perform its normal functions.

The spell protects the vessel and all aboard from the dangers of drowning and pressure, but not from damage from outside obstacles or creatures. The bubble cannot be used offensively and prevents an affected vessel from rising into a space that won’t accommodate it (like a sea cave too small to contain it or under another vessel). Creatures can enter or leave the bubble at will, but those outside the sphere cannot be forced inside against their will, the sphere proving substantial enough that such creatures may choose whether to enter or to slip away along its sides. At the end of the spell’s duration the bubble pops, causing a vessel still underwater at that time to begin sinking. This spell has no effect if cast upon a vessel in water that cannot cover it entirely.

Although largely beneficial, this spell can be cast on a water vehicle whose pilot does not want to submerge their vessel. The pilot must succeed on a Wisdom saving throw to resist this effect.

Megalodon

The true nightmare of the sea is the megalodon, a shark that represents the pinnacle of this species’ evolution. Horrifying in its immense size and ruinous appetite, the megalodon is certainly the beast behind many legends of enormous fish who swallow ships whole.

A megalodon is 60 feet long and weighs 100,000 pounds.