Blood Shade

Amorphous. The shadow can move through a space as narrow as 1 inch wide without squeezing.

Shadow Stealth. While in dim light or darkness, the shadow can take the Hide action as a bonus action.

Chilled Weakness. While hit with frost damage, the shade has disadvantage on attack rolls, ability checks, and saving throws.

Weapon Shape. Blood Shades can use their blood to form reasonable weapons of their choice and deal equivalent damage to it.

Hidden Presence. Can alternate its form to appear as a regular humanoid. Appears as a regular humanoid to all physical inspections. 

Strength Drain. Melee Weapon Attack: +4 to hit, reach 5 ft., one creature. Hit: 9 (2d6 + 2) necrotic damage, and the target's Strength score is reduced by 1d4. The target dies if this reduces its Strength to 0. Otherwise, the reduction lasts until the target finishes a short or long rest.

If a non-evil humanoid dies from this attack, a new shadow rises from the corpse 1d4 hours later.

Blood Weapon Weapon Melee Attack: +4

Scab Armor. Solidifies the exterior layer of its body to nullify Chilled Weakness. Must maintain a Concentration roll of 15 or higher.