Parasite

As Rogues excel at hiding within shadows and evading capture and damage, they are the main target for a Parasitic creature that needs a host to survive. It can enter through any opening in your body and once inside it is nearly undetectable by others, it can also freely move within your body and coat your skin with itself. Many Rogues that are chosen by the Parasite try to fight it and eject it from their body, but the few that don't tend to form a symbiotic bond with the Parasyte as they help each other survive.

Parasitic Coat

Starting at 3rd level, the Parasyte inside you gives you a new way to attack foes. As a Bonus Action you can summon the Parasyte to coat parts of your body for 1 minute. While coated by the Parasyte your Unarmed Strike gains the following features:
•Its range changes to 15ft
•It has the Finesse property
•It deals 1d6 slashing, piercing or bludgeoning damage; you choose its damage type with each attack.
You become proficient with this attack if you aren't already proficient with unarmed strikes.
You can use this feature a number of times equal to your Constitution Modifier (minimum of 1). You regain all uses after finishing a short or long rest.

Symbiotic Shield

Starting at 9th level, the Parasyte within you begins to take your well-being into a much higher consideration. While your Parasitic Coat is active you also gain a +2 to your AC.
If your Parasitic Coat isn't active you can use reaction you call forth the Parasyte to temporarily cover your body, giving you a +2 bonus to your AC for a single attack directly aimed at you. You can make this chose to activate this ability after a creature rolls for its attack but before your DM determines the results.

Two Minds as One

Starting at 9th level, the parasite in your body has gained access to your brain and can now talk to you. It talks to you only when it feels its input is needed. You gain proficiency with two of the following: Insight, Intimidation, Investigation, Perception, Persuasion or Survival.
In addition you gain advantage on Saving throws against being Charmed and Frightened

Camouflage

Starting at 13th level, you can use your Cunning Action to Hide even in plain sight. When you use this feature you become Invisible with a successful Stealth check (DC is determined by the DM). You remain Invisible until you attack or cast a spell.
You can use this feature a number of times equal to your Dexterity modifier (minimum of 1) and you regain all expanded uses when you finish a long rest.

Parasyte's Mark

Starting at 17th level, the Parasyte living inside you can attach its seed to an enemy. When you use your Parasitic Coat ability to attack a creature you can choose to mark that creature. While a creature is marked it has disadvantage on attack rolls to hit you, and you have advantage on attack rolls against it. You also gain advantage on ability checks made to track the marked creature for the next hour.
You can use this feature a number of times equal to your Dexterity modifier (minimum of 1) and you regain all expanded uses when you finish a long rest. Only one creature may be marked by this feature at a time.