Enhanced Assassin

Subjected to magical experiments, enhanced assassins are near-inhuman creatures created by the order of the twelve in their first step to creating a superhuman army. The unfortunate souls who have fallen into the hands of the order had both their minds and bodies morphed. As a result, their physical abilities have been enhanced through magical means, however, their minds have been enslaved, turning them into mere servants.
These assassins specifically are enhanced to be incredibly stealthy, blend into shadows, and have the strength and precision to kill their target in a single strike. Their bodies have been blended with a metal-like, black slime, which an assassin can warp to create weaponry and armor. The default shape into which they morph this slime around themselves represents a skin-tight suit with some parts of it enforced to protect vital areas. Additionally, they tend to create a hooded robe and a mask that covers their face up until the nose. Their preferred weapon is a pair of shortswords. The slime may also protect the identity of the assassins. Under certain conditions, whenever an assassin dies, the slime will violently erode its host and evaporate after. This mainly occurs when a subject is sent on a mission where its body cannot be retrieved or there is a risk an enemy procures it.

Traits

• Ability Strain: Some abilities of the enhanced assassin will strain their body, causing them to become exhausted. For every three levels of Strain, the assassin will gain a level of exhaustion. When exhaustion reaches third level or higher, they cannot use any abilities anymore that give a stack of Strain.
• Nimble: The assassin may take the disengage and hide action as a bonus action.
• Assassinate: During its first turn, the assassin has advantage on attack rolls against any creature that hasn't taken a turn. Any hit the assassin scores against a surprised creature is a critical hit.
• Back Stab: When making an attack from behind, any attack roll of 16 or higher on the assassin's die counts as a critical hit.
• Sneak Attack: Once per turn, the assassin deals an extra 14 (4d6) damage when it hits a target with a weapon attack and has advantage on the attack roll, or when the target is within 5 feet of an ally of the assassin that isn't incapacitated and the assassin doesn't have disadvantage on the attack roll.
• Slime Manipulator: The enhanced assassin dawns equipment made of black metal-like slime. As a result, it can mend any tears in its armor and recreate any equipment lost. Recreating a weapon will take a bonus action. The assassin can create any simple weapon and martial weapon that they are proficient with.
• Withering Weapons: Any weapon that the assassin creates using the slime they are infused with will have the wither property.
• Enhanced Jump: Whenever taking the long or high jump action, the assassin may incur 1 stack of Strain to double the distance of the jump. It may use its Dexterity modifier to make this jump.
• Multiattack: The assassin can take two actions, one of which must be a shortsword attack.

Actions

• Shortsword: Melee Weapon Attack: +9 to hit, reach 5 ft., one target. Hit: 18 (3d8 + 5) piercing damage.
• Vault: As a bonus action, the assassin can make a Dexterity (Acrobatics) check against a creature's AC to vault over them. Doing so successfully gives them advantage on any attacks made against the target that turn and Back Stab applies. On a fail, the assassin will have disadvantage on any attacks made against the target on that turn. The target must be humanoid and of medium or large size. If the creature is of large size, the assassin has disadvantage on the roll to successfully vault.
• Dimming Light: At the cost of incurring 2 stacks of Strain, the assassin can dim any source of light within a 120 feet area, reducing bright light to dim light and dim light to darkness. By sustaining an additional stack of Strain, the range of this ability extends another 60 feet.
• Shadow Walk: At the cost of incurring 2 stacks of Strain, whenever the assassin is in dim light or darkness, it can warp itself into the shadows for at most one turn. When in a shadowy form, it is hard to see, soundless, does not provoke attacks of opportunity, and cannot be blocked by physical objects. When attacking a creature in this state, the assassin makes a Dexterity (Stealth) roll contested by a Wisdom (Perception) roll by the target. If successful, the assassin has advantage on hitting the target. When the assassin was not yet known to the target, this roll is instead contested by the target's passive perception. If the target is blinded or it is in darkness and cannot see in the darkness, this check automatically succeeds. When Shadow Walking is active, the assassin is immune to all damage except radiant and force.
• Quick Dash: At the cost of incurring 1 stack of Strain, the assassin may spend a bonus action to make a short 10 feet dash. By sustaining an additional stack of Strain the assassin can add 5 feet to this dash. Additional distance may be added up to 3 times.

Reactions

• Dodge: At the cost of incurring 1 stack of Strain, the assassin may add half its Dexterity modifier (+2) to its AC. This may be used after the creature attacking the assassin rolled its attack.

STR	DEX	CON	INT	WIS	CHA
15 (+2)	20 (+5)	13 (+1)	11 (+0)	14 (+2)	8 (-1)

Type: Medium Humanoid
Armor Class: 16
Hit Points: 192
Speed: 40 ft.
Proficiency: +4
Saving Throws: Dex +9
Skills: Acrobatics +9, Stealth +9, Sleight of Hand +9, Perception +6
Damage Resistance: Poison
Condition Immunities: Charmed, Frightened
Senses: Darkvision 120 ft.
Languages: Whatever languages they knew before
Challenge: 10