Vampirism

You have been afflicted with the curse of Vampirism. This manifests in a number of powers and abilities, as well as a few drawbacks. 

Vampire: Your creature type changes to Undead. 

Shapechanger. If you aren't in running water or sunlight, you can use your action to polymorph into a Tiny bat, a Medium wolf, or a Medium cloud of mist, or back into your true form.

While in bat or wolf form, you can’t speak. In bat form, your walking speed is 5 feet, and you have a flying speed of 30 feet. In wolf form, your walking speed is 40 feet. Your statistics, other than your size and speed, are unchanged. Anything you are wearing transforms with you, but nothing you are carrying does. You reverts to your true form if you die.

While in mist form, you can’t take any actions, speak, or manipulate objects. You are weightless, have a flying speed of 20 feet, can hover, and can enter a hostile creature’s space and stop there. In addition, if air can pass through a space, the mist can do so without squeezing, and you can’t pass through water. You have advantage on Strength, Dexterity, and Constitution saving throws, and you are immune to all nonmagical damage, except the damage you take from sunlight.

Misty Escape. When you drops to 0 hit points outside your coffin, you transform into a cloud of mist (as in the Shapechanger trait) instead of falling unconscious, provided that you aren't in running water or sunlight. If you can’t transform, you are destroyed.

While you have 0 hit points in mist form, you can’t revert to your vampire form, and you must reach your coffin within 2 hours or be destroyed. Once in your coffin, you reverts to your vampire form. You are then paralyzed until you regain at least 1 hit point. After 1 hour in your coffin with 0 hit points, you regain 1 hit point. 

Regeneration. You regain 10 hit points at the start of your turn if you have at least 1 hit point and aren't in sunlight or running water. If you take radiant damage or damage from holy water, this trait doesn't function at the start of your next turn.

Spider Climb. You can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check.

Vampiric Resistances: You are resistance to necrotic damage and nonmagic damage from bludgeoning, piercing, and slashing weapons. 

Vampire Weaknesses. You have the following flaws:

Forbiddance. You can’t enter a residence without an invitation from one of the occupants.

Harmed by Running Water. You takes 20 acid damage if you end your turn in running water.

Stake to the Heart. You are destroyed if a piercing weapon made of wood is driven into your heart while you are incapacitated in your resting place.

Sunlight Hypersensitivity. While in sunlight, you takes 20 radiant damage at the start of your turn, and you have disadvantage on attack rolls and ability checks.

Bloodthirst: You must consume at least one cup of humanoid blood every 24 hours or suffer one level of exhaustion. While your thirst remains unquenched, you cannot remove levels of exhaustion. Consuming at least one cup of humanoid blood removes all levels of exhaustion applied by this trait. 

Natural Weapons: You gain a Bite attack and a Claw attack.

Natural Armor: While unarmored, your armor class equals 12 + your Dexterity modifier. You can use a shield and still gain this benefit. 

Vampirism Curse: You can pass the vampirism curse to other humanoids that you bite and consume the blood of. This trait only works if you have consumed the blood of the vampire who passed the vampirism curse on to you. Any humanoid that you pass this curse to is treated as charmed by you until they consume your blood.