Assassinate. During its first turn, the Vlos has advantage on attack rolls against any creature that hasn't taken a turn. Any hit against a surprised creature is considered a critical hit.

Evasion. If the Vlos is subjected to an effect that allows it to make a Dexterity saving throw to take only half damage, it instead takes no damage if it succeeds on the save and only half damage if it fails. It can’t use this trait if it is Incapacitated.

Sneak Attack (1/Turn). The Vlos deals an extra 21 (6d6) 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 Vlos that isn't Incapacitated.

Reckless. While in a Blood Rage, at the start of its turn, the Vlos can gain advantage on all melee weapon attack rolls during that turn, but attack rolls against it have advantage until the start of its next turn.

Sanguine Healing. While in a Blood Rage, the Vlos regains hit points equal to any necrotic damage it deals to a creature.  

Multiattack. The Vlos makes three attacks, using its Shortsword or Light Crossbow in any combination.

Shortsword. Melee Attack Roll: +7, reach 5 ft. Hit: 7 (2d6 + 4) Piercing damage plus 7 (2d6) Necrotic damage, and the target needs to make a CON14 saving throw or have its speed reduced by half until the end of its turn.

Light Crossbow. Ranged Attack Roll: +7, range 80/320 ft. Hit: 7 (1d10 + 4) Piercing damage.

Cunning Action. The Vlos takes the Dash, Disengage, or Hide action.

Shadow Jump. The Vlos teleports, along with any equipment it is wearing or carrying, up to 30 feet to an unoccupied space it can see. Both the space it teleports from and the space it teleports to must be in dim light or darkness.

Uncanny Dodge. The Vlos halves the damage that it takes from one attack that hits it. The Vlos must be able to see the attacker.

Blood Rage. As a reaction, triggered by the sight or smell of blood, the Vlos enters a blood rage, gaining resistance to bludgeoning, piercing and slashing damage from non-magical weapons, and advantage on all DEX related checks. While in a blood rage, its speed increases by 10, it gains blind sight (range 10ft), and it must succeed on a CON10 save or attack the closest creature that is below its max HP.