Parasite from the Outer Spheres

"It was nothing of this earth, but a piece of the great outside; and as such dowered with outside properties and obedient to outside laws." - H.P. Lovecraft

Out there, beyond the sky and the stars, dwell entities that defy explanation, and do not abide by the rules of petty mortals. You were a witness first hand to such madness when a star fell from the heavens and crashed into the wilds near your home. It brought with it cacophonous lightning that sundered the very sky itself. When you went to investigate you saw something that was not of this world, a thing that glowed in the most indescribably abrasive hue. Was it an animal, a plant or a creature from the depths of a far off alien ocean, you could not possibly say. Simply gazing upon the celestial petals and unnerving tentacles of no sane or wholesome colour bring a glimpse into the spheres of the infinite planes and the vast expanses beyond the stars. This insight into the nature of the universe is fleeting yet beautiful. 

Dazed into a stupor, while staring at the eldritch seed your vision goes black, and you reawaken imbued with the knowledge that something is not quite right...

A parasite from beyond the stars has infected your body and mind, but all is not without benefit. As it steadily grows, you begin to notice it has affected you in strange and unnatural ways, with abilities that you could not even describe before now right at your fingertips. And yet there is a longing within you, but whether it is yours or the parasite's you cannot know. A longing to reach out and commune with something, some entity dwelling within the dark between the stars.

That thing, whatever it is, is a part of you now.

Or are you a part of it...?

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	color spray, arms of Hadar
2nd	acid arrow, mind spike
3rd	hunger of Hadar, call lightning
4th	dimension door, Evard’s black tentacles
5th	synaptic static, enervation

Alien Constitution

Starting at 1st level, your alien parasite has altered your body in such a way that you become immune to the petty diseases of man and beast. Additionally, you become resistant to poison damage.

Parasitic Leeching

The hunger of the entity is great, and mere food cannot always sustain it. At 6th level, you can now lash out with parasitic tentacles that erupt from your flesh and latch onto an enemy within 10 ft. Make a melee spell attack contested by the enemy's Strength (Athletics) or Dexterity (Acrobatics). On a success, the target is grappled and once a day you can spend a bonus action to inflict 2d8 necrotic damage. The parasite then transfers this life essence into you, but not before taking its share. You are thus healed for half the amount of necrotic damage dealt in this way.

The tentacles deal more damage when you reach higher levels: 3d8 at 11th level, and 4d8 at 17th level.

Parasitic Rejuvenation

The parasite has grown and as such, brings new gifts. It has gained the ability to transform life force into arcane power. At 10th level, your parasite can rejuvenate your spent magical energy by draining your very life force. You can now willingly allow the parasite to inflict 2d12 necrotic upon you to regain a pact slot. You regain one pact slot for every 2d12 necrotic damage you inflict in this way.

Perfect Imitation

At 14th level, the parasite has carefully observed the behaviour and appearances of these creatures enough through your eyes and memories that it can shift and change your very body to mimic others, allowing you to cast alter self at will without expending a spell slot. Additionally, if you have used Parasitic Leeching on a humanoid, you gain their memories and can recall enough information as to be able to reliably pass off as them in conversation.