Dhampir Bloodlust

While your vampiric powers grow your bloodlust becomes overwhelming, making you dangerous to your living companions. 

While your bloodlust is not sated, when you empower your fanged bite, you deal an additional 2d6 in necrotic damage on a hit. You regain hit points equal to half the necrotic damage dealt. You may, as per the Dhampir vampiric bite, empower your fanged bite a number of times equal to your proficiency modifier. 

On a critical hit or at the DM's discretion, you must roll a Wisdom Saving Throw (DC = 10 + your Constitution Modifier) or be overcome with bloodlust. You attack the nearest creature that is not an undead or construct with your fanged bite. At the end of each following turn, you may roll another Wisdom Saving Throw to escape your bloodlust, you continue to attack this creature until you succeed this saving throw, the creature dies, or you fall unconscious. 

You may sate your bloodlust by feeding. On your turn, as an action you bite a willing, unconscious, restrained, or charmed humanoid and drain them of one pint of blood. They must make a Constitution Save (DC 10 + your Constitution modifier) or receive one level of exhaustion which lasts until they complete a long rest. This will sate your bloodlust for 1d4 days, during which you have advantage on your saving throws against the bloodlust.