Blood warden

Blood wardens are not afraid of being hurt or to hurt others. To them death is a fundamental part of life and any creature that desecrates the peace of the dead is an abomination. They have learned how to govern the blood of the living to protect the natural order. Their meticulous nature allows them to use their own life force to empower their abilities or grant boons to their allies or control the life force of others either harming or healing them. Deities that watch over blood wardens include Kelemvor, Wee Jas, the ancestral spirits of the Undying Court, Hades, Anubis, and Osiris, Serenrae, The raven Queen. Followers of these deities seek to put wandering spirits to rest, destroy the undead, and ease the suffering of the dying.

Sanguine study

Whether bestowed by your God, or your own personal study - you have become incredibly familiar with blood and it's normal uses, as well as others which are now open to you due to your connection with your deity. You can now magically extract and seal blood into appropriate vessels - vials or bottles, or some other appropriate sealable vessel. This mechanism involves the voluntary removal of blood from a living being, storing it in the vessel and sealing it with magic in a way which only you can open. These vessels maintain their usual durability and so it should be taken care not to damage them. 

Starting at level 1, you gain the ability to extract and store the blood essence from other individuals. During a long rest, you can magically enchant up to 5 vessels to be ready and available to store blood. You gain proficiency in medicine.

Over the course of an hour, you can remove blood essence from 1 unwilling creature or over 1 minute from a willing or unconscious one. This blood essence must be kept in appropriate vessels as described above, and kept on your physical person at all times. 

Your connection to blood allows you to channel spells through it. You can cast a spell on one of your vessels and the owner of the blood essence will be the recipient of the effect. Doing so you do not need to see the target or be near it disregarding any range and sight restrictions of the spell you choose to cast. You can use this feature a number of times per long rest equal to your Wisdom modifier (minimum of 1)

Additionally, you can use a vessel of blood as a spellcasting focus for your cleric spells. 

Violent outburst

You have learned how to empower your spells trough infusing your own life force into them. Starting at level 1 you can choose to spend some of your health (2d6) to add an extra damage/healing die to your spell attacks or healing spells. Once you do that the spell becomes unstable and has a chance to fail. For every extra die you add 3 to the fail score (1 extra die, the spell fails on 1-2-3 on our d20 roll, you roll a d20 for healing spells to check if they fail too). You can empower a single spell more than once (you can choose to empower it for +1,+2,+3,+4  of its damage/healing die, however you have to pay the health cost for each empowerment and the fail chance increases proportionally ). You can use this feature a number of times equal to your proficiency bonus and you regain all uses when you finish a short or long rest.

If a spell would fail it creates a magical explosion of blood with 10ft radius centered on you that does the same amount of damage as the spell you were casting (same number of damage/healing dice)  to all creatures in the area (dexterity saving throw against your spell DC for half damage)

Channel Divinity: Blood Curse

Starting at 2nd level, you can use your Channel Divinity to link the lifeforce of two creatures.

As an action, you choose two creatures you can see within 30 feet of you, cursing them until the end of your next turn. For the duration whenever one of the creature takes any damage, half of it (rounded down) is transferred to the other creature. This curse ends early if one of the creature dies.

Essence link

Beginning at level 6, as a bonus action/reaction you can create a link between you and an ally of yours, that you can see and who's blood essence you have collected and is currently in your possession. While linked you can take half of the damage of the next attack or spell effect that hits the target. The link is active until the start or your next turn. If you are in the possession of a blood stone you extend its features to the linked target.

Potent links

Starting at level 8 whenever you heal a target that you are currently linked to you get healed for half of that amount.

Master of essence

Starting at level 17  you have achieved mastery over transferring of lifeforce. As an action you can link up to 6 other creatures to you for 1 minute. While under this effect you can use your reaction redistribute half (rounded up) of any damage taken from one of the linked creatures to another (happens after the DM announces the total damage), Also whenever you heal a creature all other linked creates are healed for the total amount healed divided by the number of linked creatures.