Vampirism

You have been tainted with the curse, or blessing, of vampirism. It takes 1d4 days for you to fully become a vampire, during which you feel ill and become poisoned, even if you have immunity to it, and a Remove Curse spell and similar effects will cure you from the curse. Also you undergo a physical transformation, gaining the following physical characteristics:

• Your skin become as pale as your original coloration would allow. (i.e. if you had light skin, it becomes marble white in colour, tanned skin becomes cappuccino white and so on)
• Your iris changes coloration, into either red, white or it's original colour becomes more vivid, and have an eerie glow, visible through non-magical darkness.
• Your canines elongate, becoming vicious fangs.
• Your facial features overall obtain a macabre beauty, becoming more attractive.
• Your ears become noticeably pointed at the tips, but still shorter than elven ears.
• Your nails harden and polish.

Once fully transformed you become a vampire, and gain the following benefits. Nothing short of a Wish Spell can cure you now.

Insatiable Hunger

After a long rest roll 1d6 and that result will be how many hours the character has to feed on enough blood to sate their hunger otherwise they will go into a berserk frenzy where they must  attack the nearest living creature of medium size or larger with the most efficiency possible (bonus action attacks, spells, etc.) to drain the target of its blood, they will not be able to break the effect until their hunger is satiated.
(at 5th level dice roll changes to 1d8, and at 9th level it changes to 1d10.)

Darkvision

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.

Deathless Nature

You don’t need to breathe.

Sunlight Sensitivity

You have disadvantage on attack rolls and on Wisdom (Perception) checks that rely on sight when you, the target of your attack, or whatever you are trying to perceive is in direct sunlight. You also gain vulnerability to Radiant Damage.

Spider Climb

You have a climbing speed equal to your walking speed. In addition, at 3rd level, you can move up, down, and across vertical surfaces and upside down along ceilings, while leaving your hands free.

Vampiric Bite

Your fanged bite is a natural weapon, which counts as a simple melee weapon with which you are proficient. You add your Constitution modifier, instead of your Strength modifier, to the attack and damage rolls when you attack with this bite. It deals 1d4 piercing 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.

When you attack with this bite and hit a creature that isn’t a Construct or an Undead, you can empower yourself in one of the following ways of your choice:

• You regain hit points equal to the piercing damage dealt by the bite.
• You gain a bonus to the next ability check or attack roll you make; the bonus equals the piercing damage dealt by the bite.

You can empower yourself with this bite a number of times equal to your proficiency bonus, and you regain all expended uses when you finish a long rest.