A laboratory experiment captured from a Xenos entity living deep in the Astral Sea, this virus comes sealed in a vial and slowly shifts and moves, as if endlessly exploring the vial's interior. To attune to this item, you must first drink the contents of the vial, unlocking the following properties.

Symbiotic Enhancement. Your body is forced into peak condition. Your Strength, Dexterity or Constitution Score is set to 20. The virus has no effect on the stats that are equal to or higher than 20 already.

Resistant. While attuned to the Strain, you have Immunity to poison and acid damage, and you're immune to the poisoned condition. You are also to always be considered diseased. You gain resistance to all nonmagical attacks.

Morph. You can cause your arms and hands to morph, harden and change to assume the shape of any mundane melee weapon, causing your unarmed strikes to gain the properties of that weapon except for the thrown and special properties (if any). Attacks made with this morph weapon are still considered an unarmed attack. Attacks made with your unarmed strikes are considered magical for the purpose of overcoming resistances and you have a +3 to attack rolls and damage rolls made with your unarmed attacks. You can also make your body Amorphous as a Bonus Action. For the next minute, you (along with any equipment you're wearing or carrying) can move through a space as narrow as 1 inch wide without squeezing. Once you use this property, it can't be used again until you take a short or long rest.

Adrenaline. When you would be reduced to 0 hit points, you can choose to drop to 1 hit point instead. If you fall below 10 hit points, you can can choose to enter into a state of intense adrenaline. Until the start of your next turn you are immune to all damage. For one minute you gain advantage to all rolls. Once used, this property can't be used again until the next dawn.

Symbiotic Nature. If you are incapacitated but not stunned, you can allow the Virus to take control of your body for the duration, allowing you to act. You are only limited to attack, dodge, dash, disengage and movement. The Virus can't be removed from you while you're attuned to it, and you can't voluntarily end your attunement to it. If you are targeted by a spell that would end curses, you can make a DC 20 Charisma Saving throw to resist the Virus from leaving you. The virus exits your body on a failure. If the virus is forcibly expelled, your Strength, Dexterity and Constitution Scores are set to 3 until you finish a long rest.

If you die while the virus is inside you, it bursts out and scampers away. Hiding and following your corpse until you are revived. Should you be revived in a new body, the virus will cease its pursuit.