Fathomless Warlock
Subclass Icon courtesy of wequeen.


Based on the Fathomless Patron for Warlocks in 5e.
Requires Script Extender
Requires Compatibility Framework.
Requires Veenab Spells
Compatible with 5e Spells. Works even if you don't have 5e Spells.
This class does not go past level 12 and doesn't plan to.


Level 1 - Tentacle of the Deep

Gain Tentacle of the Deep and Command: Tentacle as Class Actions.
As a Bonus Action, conjure a spectral tentacle. The tentacle cannot be harmed and will not be targeted by enemies.
The tentacle cannot make any actions unless you use your Bonus Action to cast Command: Tentacle.
The tentacle will automatically be commanded when first summoned.
The number of times you can use this feature is based on your Proficiency Bonus, refreshing after a Long Rest.



Once commanded, the spectral tentacle can use its two abilities, Abyssal Lash and Deep Dive.
Abyssal Lash acts as it's attack. The tentacle strikes an enemy within 3m, dealing 1d8 Cold damage and reducing their Movement Speed by 3m. 
Deep Dive acts as its movement. The tentacle dives below and reappears at a location within 12m.


You can also take the Larian-ized version of this feature instead.
If you do, the Spectral Tentacle gains the ability to act independently from the summoner, same as other summon abilities.
To make it a bit fairer, the independent tentacle can only move 9m, whereas the commanded tentacle can move an increased 12m.



Level 1 - Gift of the Sea

Gain the Gift of the Sea Passive.
While you are on a water-based surface, you gain +3m of movement.



Level 6 - Oceanic Soul

Gain the Oceanic Soul Passive.
Grants you resistance to Cold damage.



Level 6 - Guardian Coil

You gain the Guardian Coil as a Reaction.
Your spectral tentacle gains the Guardian Tentacle Aura.
When you or an ally within 3m of your spectral tentacle would take damage, you can use your reaction to reduce the damage you/they would take by 1d8.
This ability is a bit finnicky and may have some issues.
 
 
 

Level 10 - Improvements
Abyssal Lash now deals 2d8 Cold damage and Guardian Coil can reduce damage taken by 2d8.
You will get a separate guardian coil passive, so be sure to disable to weaker version.



Level 10 - Grasping Tentacles

At level 10, gain the Grasping Tentacles passive. 
Gain Evard's Deep Sea Tentacles as once per long rest spell, and Evard's Black Tentacles as a warlock spell. They are both functionally identical.
Whenever you cast Evard's Deep Sea Tentacles or Evard's Black Tentacles, gain temporary HP equal to your warlock level.
Additionally, damage cannot break your concentration when you cast the aforementioned spells.



Subclass Spell List
Level 1 - Create or Destroy Water, Thunderwave
Level 2 - Gust of Wind, Silence
Level 3 - Lightning Bolt, Sleet Storm
Level 4 - Control Water, Ice Storm
Level 5 - Maelstrom, Cone of Cold

Bigby's Hand competes with your spectral tentacle as a summon and I chose to replace it with Maelstrom.
Summon Elemental was replaced with Ice Storm because it's just not even better than Conjure Elemental.



Other
Frostbite
- Evocation Cantrip. Con Save.
- Deal 1d6 Cold damage to an enemy and inflict disadvantage on their next attack.


Thunderclap
- Evocation Cantrip. Con Save.
- Deal 1d6 Thunder damage to all enemies within 2m of you.


Control Water
- Level 4 Transmutation Spell
- Concentration.
- Once cast, you can recast this spell without expending a spell slot for 10 turns.
- All of its effects leave water at target locations. All effects deal half damage on a successful save.
- You can choose between Whirlpool, Tidal Wave, and Water Spouts.
- The free recast versions of each variation cover a smaller radius.
- When upcast with a level 5 spell slot, they gain an extra damage dice.
Whirlpool
- Summon a whirlpool that knocks around creatures in a 6m radius and pulls them towards the center.
- Those that fail a Strength Saving Throw take 2d8 Bludgeoning damage and have their movement speed halved.
Tidal Wave
- Conjure a powerful wave that crashes into creatures in a 6m radius.
- Creatures that fail a Strength Saving Throw take 2d4 Bludgeoning damage and are knocked Prone.
Water Spouts
- Conjure 3 pillars of water, each with a 2m radius.
- Creatures caught by it must succeed a Dexterity Saving Throw or take 2d8 Bludgeoning damage.


Maelstrom
- Level 5 Evocation Spell
- Concentration.
- Summon a 9m radius sphere that lasts 10 turns. The area becomes difficult terrain.
- Any creature that starts their turn inside it must succeed a DC19 Strength Saving Throw or take 6d6 Bludgeoning damage and be pulled towards the center.
- Maelstrom is supposed to be a water-based storm, but I have to reflavor it to be wind based since there's no water storm animation in the game.
- It has a flat DC value of 19 because the storm it just a summoned object with a giant aura rather than a spell effect.
- This is really big and lags the game when initially cast and when it ends.