Xolotl saved you from your first death and Taydentavia, he told you he was imprisoned by Kulkan and now you have to free him.

Some of his life essence was absorbed by you at your birth, this created a bond you never knew even existed.

Blood Pact

Starting at 1st level you can feel all creatures with blood in a range of 40 feet, even if those are hidden behind a wall of magic barriers.

Percieving their blood, the warlock can recognize their size and species.

Expanded spell list

With this patron you gain the use of more spells.

Hemomantic current

Starting at 6th level, you can sneak through small cracks as if they were difficult terrain.
Becoming a blood trail, you are now immune to fall damage but a porous soil or grates may make you fall.

Lend of life

Starting at 10th level, you can take possession of others' vital essence.

After hitting a creature with an object (piercing or sharp) or after finding a creature with blood that has been cut or pierced, you absorb 2d12 HP that will be dealt to the creature as damage.

The creature must make a Constitution saving throw. A target takes 2d12 damage on a failed save, or half as much damage on a successful one.

You can use this feature only once a short rest.

Uroboro

Starting at 14th level, your blood cellular metabolism is at his maximum power and control.

Non magic wounds start healing instantly avoiding bleeding.
Every amputated limb will conncet immediately withouth even falling off.

This grants control on the circulation of oxygen in the body, allowing you to breath and hold breathing in absence of enough oxygen.