Sorcerer Level	Feature
1st	Parasitic Familiar
6th	Immutable, Infected Boon
14th	Infect Host
18th	Flesh Walker

Parasitic Familiar

At 1st level, you develop sentient parasite that resembles a large discolored abscess that acts as your familiar and grants you several bonuses as long as you remain infected.

• You gain resistance to poison damage
• You have advantage on saving throws against diseases
• You are proficient in Constitution saving throws
• You gain advantage on a Strength or Dexterity skill or ability check once per short or long rest
• Once per long rest you can roll any number of hit dice, taking damage equal to the amount rolled, and recover a number of sorcery points equal to half the damage, minimum 1

The parasite is hardier than other familiars, however it takes a tole on your body. Each time you gain another level you gain 2 fewer hit points, minimum 1, and it has 2 hit points per level in this class. Any time you would take damage the parasite takes damage equal to half that amount. if it is reduced to 0 hit points you lose all benefits until it regains hit points.   Whenever magic is used to heal you, it heals the parasite first, and the parasite regains all of its lost hit points after you complete a long rest. Additionally If you are targeted by a lesser restoration, remove curse, or greater restoration spell you must make a Constitution saving throw. On a failed save the parasite is reduced to 0 hit points, and you gain the poisoned condition for 1 hour.

Immutable

Beginning at 6th level, as long as you are infected with your parasite familiar you gain advantage on saving throws against poisons, and being polymorphed.

Infected Boon

At 6th level while you are infected with your familiar you can use an action to spend 2 sorcery point to gain an infected boon. Infected boons last for until you complete a short or long rest, and you cannot have more than one infected boon at a time.

Infected Boon	Effect
Chitin	Your skin grows stiff and leathery. Your armor class equals 14 + your Dexterity modifier, and your speed is reduced by 10 feet, cannot fly, and have disadvantage on ability checks while swimming.
Cold Sweat	Your parasite pumps chemicals through your body granting you temporary hit points equal to 1d8 + your Constitution modifier, and have disadvantage on Strength, and Dexterity ability checks.
Fever	Your parasite moves into your head, granting you advantage on Intelligence and Wisdom saving throws, but disadvantage on Initiative rolls, and Perception skill checks
Vomit	You raise the toxicity of your blood and bile, and can store a large amount of access fluid in your abdomen. As an action you can produce a 20ft cone of poisonous acid, creatures in the area must make a Dexterity saving throw or take 3d6 acid damage. You have the poisoned condition until you use this ability. Once you have used this feature, you cannot use it again until you chose a new Infected Boon

Infect Host

Beginning at 14th level you are able to infect others with your familiar. As an action you can force one creature within 30 feet of you to make a Constitution saving throw. On a failed saving throw the target is infected with your parasitic familiar, and can make a new save after completing a long rest, on a successful saving throw the target is no longer infected, and your reappears after you complete a short or long rest.   While another host is infected with your familiar you lose any bonuses or boons currently active, and you cannot use any of your familiars abilities. As long as you and the infected creature are on the same plane you can use your action to see the the infected creature's eyes and hear what it hears until the start of your next turn, gaining the benefits of any special senses that the creature has. During this time, you are deaf and blind with regard to your own senses.   While the creature remains infected you can sacrifice a 5th level or higher spell slot to cast Dominate on the creature. While the creature is dominate you can cast touch spells and spells that rely on sense through it, such as detect magic. When the infected creature takes damage your familiar takes damage equal to half the amount. If your parasite is reduced to 0 hit points while infecting another host it is cured, and the parasite reappears on you after you complete a long rest.  

Flesh Walker

At 18th level once per long rest you are able to decompose your form as an action leaving behind a cloud of spores. All creatures within 5 feet of you must make a Constitution saving throw or gain the poisoned condition. For 1 minute you become a living disease and can inhabit and infect others. While in this form you you are immune to Acid, Cold, Electric, and weapon damage, and you cannot cast spells.   While you remain in this form you can force other creatures to make Constitution saving throws by moving through them. On a failed save the creature takes 1d6 acid damage, 1d6 poison damage, and is poisoned for 1 minute. If a creature fails the save by 5 or more you can chose to inhabit the creature. While you inhabit a creature you can cast enchantment and illusion spells, but they can only target the inhabited creature.   When the infected creature takes damage you take half the amount. If the infected creature dies you appear next to them at the start of your next turn. If the creature is targeted by a lesser restoration, remove curse, or greater restoration spell you must make a Constitution saving throw, on a failed save you take 3d10 damage and appear next to the creature.