Your fanged bite is a natural weapon, which counts as a simple melee weapon with which you are proficient. You add your Strength modifier, to the attack and damage rolls when you attack with this bite. It deals 1d4 piercing plus 2d6 Fire damage on a hit. While you are missing half or more of your hit points, you have advantage on attack rolls you make with this bite. You gain as many hit points as the damage you dealt. When biting a target, they must succeed a WIS save against your WIS check or become Charmed due to the Vampiric Venom in which produces an addictive surge in dopamine.  

You gain the ability to dual wield heavy weapons as if they were light, ignoring weight, dual wield weight and two handed restrictions, allowing you to dual wield heavy objects

As a Half-Undead Celestial, you take an additional die of damage from silvered weapons. When splashed with Silver Oil you gain Silver Poisoning. Due to this fear, you do not go near anyone with silver weapons or silver oil, preferring to stay out of range. Wounds made by Silver Oil or Silvered weapons show with a reflective black mark.  

• Silver Poisoning. When splashed with Silver Oil you must succeed a DC17 CON save or take 2d6 Poison damage. During this you have disadvantage on ability checks and your Vampiric Disguise ability is negated. You also run out of blood faster during this. Every turn you must repeat the CON save until you succeed, in which the Poisoning stops.  

As a Half-Vampire you also retain the weakness of a wooden stake to the heart. If you take a wooden stake to the heart, you become Paralyzed until the stake is removed. You also take an additional die of damage when stabbed with a wooden stake. If stabbed in the heart with a wooden stake your Blood Rage is negated until the stake is removed

You can see in dim light within 60 feet of you as if it were bright light and in darkness as if it were dim light. You discern colors in that darkness as shades of gray. You cannot be affected by Magical or Normal darkness to this range. 

You don't need to breathe. You also require blood to survive. Each day you must consume blood or suffer Exhaustion. Instead of Sleeping you enter a trance for 8 hours, you also gave resistance to sleep effects

You can speak, read and write Infernal, Common and one other language of your choice.

Increase one ability score by 2 and increase a different one by 1 

Using a Bonus action you can reveal your fiendish form. In this form you have either grey or crimson skin, devilish horns, red glowing eyes, claws, a tail and demonic features. When revealing this form, any hostile that can see you must succeed a contested WIS save against your CHA (Intimidation) check. On a success nothing happens. If they fail, they become frightened by you. 

At 5th level, as many times as your proficiency bonus you can use a bonus action to form two Devilish wings in which you can use to fly up to 60ft.