Idolizing Ker, the goddess of violent death, The Keres thrive in the middle of a battlefield.  Build up Ichor and use it to increase the carnage in a fight. 

Cloak of Ichor

3rd level Way of The Keres class feature:

Gain Ichor whenever you are adjacent to a creature when they suffer damage.  This can be the vital essence that the creature needs to continue living, such as the creature's blood.  You are able to use that creature's life energy as your own.

You gain 1 Ichor whenever the following occur:

• You deal damage with a melee attack.
• You land a critical hit with a melee attack.
• You are adjacent to a creature when they fall below half of their total hit points.
• You are adjacent to a creature when they fall to 0 hit points.

Once you have gained any amount of Ichor, the following effects apply (these effect persist until you are cleaned even if you have 0 remaining Ichor):

• You have disadvantage on all persuasion and  medicine checks. 
• You have advantage on all intimidation checks.
• You have disadvantage on saves made against diseases.

You may use your accumulated Ichor for the following:

• As long as you has at least 1 Ichor, you are immune to the frightened condition.
• As a Bonus Action, spend 2 Ichor to regain 1 Ki point.
• When you use your Quickened Healing ability, you may spend 2 Ichor to perform it as a bonus action instead of an action.
• When you hit with a melee attack, spend 1 Ichor to have the target make a Wisdom Save; on fail the target becomes frightened of you until the start of your next turn.  On a success the target cannot be targeted by this ability until the start of your next turn.

When you take a short or long rest, your Ichor resets to 0 and you are considered "cleaned" as far as the effects of Ichor are concerned. 

Sacrifice

3rd level Way of The Keres class feature:

As an Action, roll your martial arts die and add your Wisdom modifier.  Deal that much damage to yourself and gain that many Ichor.

Red Spector

6th level Way of The Keres class feature:

You know the Misty Step and my cast it using 3 Ichor.

When you are the target of an attack, you may spend any amount of Ichor as a Reaction, add half of the Ichor spent (rounded down) to your AC until the start of your next turn.

Field Hematologist

11th level Way of The Keres class feature:

Your control over Ichor improves; you gain the following:

Crimson Condensation: As an Action, you may spend up to 6 Ichor.  When you do regain Ki equal to half of the Ichor spent (rounded down).

Deeper Sacrifice: When you use your Sacrifice ability you may roll one of your hit dice and add it to the amount of Ichor that your gain.

Blood Puppetry: Whenever you force a target must save, you may spend any spend up to 6 Ichor to increase the DC by half of the Ichor spent (rounded down).

Red Rain

17th level Way of The Keres class feature:

As an action, you cause an explosion of blood and ichor centered on you. You consume all Ichor that you currently have and every creature within 30 feet of you must make a Dexterity Save. Targets that fail take force damage equal to 1d10 for each Ichor consumed plus your Wisdom modifier; half that damage (rounded down) on a successful save.

You gain 1 Ichor for every target is brought below half HP or to 0 HP as a result of this ability.

If you do not gain any Ichor from this ability, you are considered "cleaned" as far as the additional effects of Ichor are concerned.