Vampirism

You have become... a vampire. 

Benefits:

• Increase your Charisma score by 2, to a maximum of 20.
• You gain Proficiency in Deception and Persuasion.
• You are Immune to Necrotic Damage.
• You learn the misty step and charm person spells. (You may use these spells once a day, unless you are a spell caster, and may use a spell slot of the corresponding level. Your Spell save DC is based on your Constitution)
• You have an innate climbing speed of 30 feet and can cling on to surfaces similarly to the spider climb spell.
• While not in Direct Sunlight or Running Water, as a Bonus Action you may Transform into a Bat. The bat has 1 Hit Point, however any attack that succeeds on the Bat form does not transfer the damage to your normal form. You can perform this transformation up to your proficiency bonus per day.
• You gain Advantage on Persuasion and Deception checks on humanoids when requesting to enter homes and similar establishments. 
• You are immune to aging and effects, magical or otherwise that effect aging. You cannot die as a result of age, and are immune to disease. 
• You gain Darkvision up to 60-Ft.
• Your Unarmed Strikes become 1d4 Slashing Damage, of which you are proficient.

Flaws:

• When you start your turn in running water, you take 3d6 Acid Damage.
• When in Direct Sunlight, you have disadvantage on Attack Rolls and Saving Throws. You have Disadvantage on Perception checks that rely on Sight.

Exposure for over 1 hour Incurs 1 level of exhaustion. For 3 Hours you begin to take 3d6 Radiant Damage for every following hour. After 5 Hours, You catch on fire, taking 1d4 Fire damage every turn you are in direct sunlight.

This can be avoided if you are completely covered be means of cloaks, and wraps or similar clothing protecting your skin. Instead 1 Level Exhaustion occurs every 4 hours if a short rest is not taken in shade.

• You are not permitted to enter a household or similar establishment without being invited. When attempting to enter, you feel the compulsion to wait and ask. If forced in, your body evaporates and reappears at the entrance, similar to a misty step spell, causing 2d10 Bludgeoning damage.
• You are Vulnerable to Radiant Damage aside from the damage caused by Direct Sunlight.
• You are Vulnerable to Silvered Weapons

Caveats:

• You must feed on blood, or turn feral. Feeding on blood, using your Vampiric Bite will stave your hunger for 1d4 days. Feasting on a humanoid (drinking 1 gallon of blood) staves your hunger for 4d4 days. After the time which your hunger is staved, you feel the increasing need to feed on blood. If no humanoid blood is consumed after 48 hours, your Intelligence score drops 2 points every following day, until you have an intelligence score of 2. You are no longer a humanoid, and cannot increase your intelligence by any means short of a wish spell. You become a feral vampiric monster who only wishes to feast on blood. 
• Your Vampiric bite may replace one of your attacks on an Attack Action. You can use this attack up to your proficiency bonus. You are proficient with this attack, and on hit does Piercing damage and 2d6 Necrotic damage. You gain hit points equal to the amount of necrotic damage dealt, unless you are at maximum, where you would gain temporary hit points instead (Temporary Hit Points do not stack).
• Reducing a humanoid to 0 HP, or using your Vampiric Bite on an unconscious creature at 0 HP, will create a Vampire Thrall after 48 Hours, unless the body is decapitated, or cremated. This thrall is undead and does your bidding. It understands the languages it did in life, but you may communicate with it telepathically, and it understands your commands.
• While you do not need sleep, you are required to rest your physical body for at least 4 hours a day in shade. 

• At the DM's Discretion, you may become Undead. Depending on how your spells or abilities work, this may be a detriment or a boon.