The Parasite

Starlog Entry 538: This is space crew Anthony Rogers reporting our recent successful excavation of the Kuiper asteroid. Minimal damage to equipment and sanitization protocol went smoothly. Note discolored rash received on arm, revealed after suits were removed post-decontamination. Treatment being administered by Doc Heather, says it's probably just athletes foot. Marvin recommends rest and relaxation for a bit.

Starlog Entry 544: Anthony Rogers reporting again. Passed the Goliath cluster today, the transit proceeds as normal. Rash has spread to elbow, more drugs and additional sanitation protocols recommended and performed by Heather. Marvin says I should be getting more to eat. This headache has also painful, requisitioning more acetaminophen from Heather.

Starlog Entry 553: Doctor Heather Gram reporting. We've stopped at remote planetoid X29B to gather raw materials and treat crewmate Anthony Rogers. His conditioned has worsened, fever and convulsions have warranted securing him in the medipod for stabilization. Patient keeps speaking aloud with a 'Marvin', there are no crew members who go by that name. Propose humane euthanisation to release patient from delirium and pain?

Starlog Entry 556: (Screaming and sounds of distress with Anthony Roger's voice rising above all) AHAHAHAHAHHAHAHAHAHAHAHAAHHAHAHAHAAHAHHAHAHAAHA ~End of starlogs~

You have been infected by some kind of near-undetectable creature. It could be an alien worm burrowed into your body, a demon trying to possess you, or some kind of virus that affects your mind. Whatever its origins, it currently attempts to wrest control of your body away from you. You are able to exert your will to resist the parasite's influence while taking advantage of the new abilities it grants you. You become faster, stronger, and more resilient. You also begin to learn how to manipulate the magics associated with the parasite's presence. For now, you form a sort of pact with this invader, but eventually, only one of you will remain as the parasite grows stronger. Who knows what kind of beast will be born should you fail to overcome it? Conversely, what kind of new powers will be made available to you should you manage to silence its gnawing permanently?

Expanded Spell List

The Parasite lets you choose from an expanded list of spells when you learn a warlock spell. The following spells are added to the warlock spell list for you.

Parasite Expanded Spells

Spell Level	Spells
1st	feather fall, false life
2nd	see invisibility, hold person
3rd	fear, fly
4th	blight, stoneskin
5th	insect plague, contagion

Parasitic Takeover

Starting at 1st level, even when your body fails, the parasite will see its mission through. The parasite returns some of your stolen vitality when you are nearing death. You gain advantage on death saving throws. When you are stabilized, you may regain 1 health. You can recover 1 health this way once per long rest.

Adaptation

Starting at 6th level, your parasite begins integrating and melding with your body, granting you increased physical capabilities. You gain a climbing speed equal to your walking speed as your limbs and body get re-structured from the parasite's machinations. This climbing is the same as Spider Climb: you climb without needing to use hands/arms.

Starting at 10th level these adaptations further improve your agility, granting you 5 additional feet of walking movement speed.

Evolution

Starting at 10th level, the parasite's reach is seen all over your body. You begin growing some kind of fleshy armor that protects you. This fleshy armor increases your armor class by 1 as well as resistance to a damage type based on the following choices:

Metastasizing Flesh

Your armor mutates and regrows quickly in response to cell death. You gain resistance to necrotic damage.

Padded Armor

Your armor is able to withstand shockwaves and protect you from sound-based attacks. You gain resistance to thunder damage.

Waxy Carapace

Your armor protects from corrosion. You gain resistance to acid damage.

Metamorphosis

Starting at 14th level, only you or the parasite remain after an intense battle of wills. Choose which entity takes over for good. If you win, you become The Symbiote and are able to utilize the parasite a floating caster as the two of you enter a mutually beneficial relationship. If the parasite wins, you become The Thing and your brain is taken over, you are now able to utilize a violent outburst of biological weaponry.

The Symbiote

You have dominated the parasite and can utilize its magical abilities for your own purposes. As a bonus action, you can have the parasite temporarily detach from your body for up to 1 minute. The parasite becomes a floating, spectral being like a Mage Hand. The parasite can’t attack, activate magic items, or carry more than 10 pounds. While the parasite is detached, you are able to cast spells as if they were cast from wherever the parasite is, whenever you cast a spell you may have the parasite fly up to 30ft before casting the spell. The parasite teleports back into your body when the 1 minute duration is up or if it is ever more than 30ft away from you. Once teleported back, it cannot detach again until after you complete a short or long rest.

The Thing

The parasite has successfully taken full control of your body. It retains vestiges of your personality but is brutally violent. You are able to unveil your true parasite form and lash out with sharp tendrils at creatures in front of you. Using an action your body unravels, revealing the true form of the monster within. Spiked and bladed limbs lash out at creatures in a 15ft cone in front of you. Each creature within this cone must make a dexterity saving throw with your warlock spell save DC. On a failed save they take 10d10 slashing damage, on a success, they take half damage.

You can unleash your true form this way once per long rest.