The Tarrasque

Your patron is the infamous being of carnage and destruction, the Tarrasque. It lays dormant for centuries at a time and seeks only carnage and food, its hunger and bloodlust may never be sated, but through the destruction and death that you cause, it can be fulfilled slightly, The Tarrasque may not be the smartest of beings, but as you feed it, you have a symbiotic relationship, and it vows to leave you alive throughout its chaos, it is a monster of its word when it comes to being fed forever.

Feed the Beast

Starting at 1st level, when you kill a creature, unless you will against it, its body is sent to the Tarrasque to feed on. The Body vanishes from its current location and cannot be located with magic. This applies to all organic beings, any items on the creature are not sent.

For each body sent to the Tarrasque, you are given Bloodlust points depending on the dead creatures Challenge Rating(CR).

Creatures sent to the Tarrasque that have below 1 CR give 0 Bloodlust points.

You can use your Bloodlust points by adding them to any of your rolls, you may use up to 10+Your Warlock level per Short Rest

You may have up to 20+Your Warlock level Bloodlust points.

Expanded Spell List

The Tarrasque's power grants you an expanded spell list, you do not gain a large number of spells, as the Tarrasque itself is not too magically inclined.

Tarrasque Expanded Spells

Spell Level	Spells
1st	mage armor, wrathful smite
2nd
3rd
4th
5th	destructive wave

[Due to DnDbeyond limitations i cant actually make the spells go into the spell list, since the Player's Handbook is licenced content, so youll have to manage that yourself]

Feeding Frenzy

 

Once per Long Rest, as a reaction, you can spend 5 Bloodlust points to enter a Feeding Frenzy, in a Feeding Frenzy, you can make an attack on your next turn as a bonus action, and for your next turn, you get an extra 1d4 Bloodlust Points for whatever you kill.

Frightful Presence

Starting at 10th level, you can spend 7 Bloodlust points to emit the Tarrasque's frightening presence, all creatures must make a Wisdom Saving Throw with a DC equal to your Warlock Level + 5, if they fail, they become afraid of you.

Spiked Carapace

Once per short rest, as a bonus action, you may spend 10 Bloodlust points to evoke the power of the Tarrasque's Spiked Carapace.

When this is active, all enemies that make a melee attack against you take 1d4 Piercing damage, and all ranged attacks have disadvantage on hitting you, this lasts one minute.