Legendary Resistance (3/Day). If Zed fails a saving throw, he can choose to succeed instead.
Contempt for the Weak. Once per turn, Zed's attacks deal extra 24 (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 Zed (including Living Shadows) that isn't incapacitated and Zed doesn't have disadvantage on the attack roll.
In addition, when Zed attacks a creature that is below half their maximum hit points, he critically strikes on a roll of 19-20 on the d20.
Evasion. If Zed is subjected to an effect that allows him to make a Dexterity saving throw to take only half damage, Zed instead takes no damage if he succeeds on the saving throw, and only half damage if he fails.
Shadow Stealth. While in dim light or darkness, Zed can Hide with advantage.
Shadow's Sight. Zed's darkvision is not inhibited by magical darkness and has a range of 120ft. Creatures cannot benefit, against Zed, from invisibility (spell or traits) while in dim light or darkness.
Master Ninja. Zed has advantage on checks and saves to see through illusions and deceit. Additionally, Zed has access to the Rogue's Cunning Action feature and a 15-foot bonus to his speed.

Multiattack. Zed makes two Shadow Blade or Razor Shuriken attacks. Zed may replace one attack with a Shadow Slash.

Shadow Blade. Melee Weapon Attack: +12 to hit, reach 5 ft., one target. Hit: 16 (2d8 + 6) piercing damage plus 12 (3d6) psychic damage. On a roll of 20 on the d20, unless the target is immune to psychic damage, the target’s Strength score is reduced by 1d6. The target dies if its Strength is reduced to 0. The reduction lasts until the target finishes a short or long rest.
If a non-evil humanoid dies from this attack, a shadow  rises from the corpse 1d4 hours later.
Razor Shuriken. Ranged Weapon Attack: +11 to hit, range 40/80, one target. Hit: 11 (1d8 + 6) slashing damage.
Living Shadow. Zed uses the Shadow Technique to make a perfect clone of himself out of shadows. The clone appears in an unoccupied space within 25ft. of him and is indistinguishable from the real Zed. 
Living Shadows have an AC of 15, 20 hit points, resistance to all damage except magical bludgeoning damage, slashing damage, and piercing damage; Vulnerability to radiant damage and Immunity to necrotic damage and psychic damage.
Additionally, clones mimic Zed's attacks and use the same tactics he does.
Shadow Slash (Recharge 4-6). Zed slashes in a 10-foot radius around himself with blade and shadow. Creatures in range must succeed a DC 18 Dexterity saving throw, taking 12 (3d6) slashing damage and 8 (2d6) psychic damage on a failure or half as much on a success.

Death Mark (Recharge 6). Zed becomes impermeable shadow, passing through a creature's chest within 10ft. of him. That creature becomes marked until initiative count 20, 2 rounds later. All damage Zed and his Living Shadows deal during that time is dealt again as psychic damage, that cannot be resisted, at the end of the mark's duration. The target can make a DC 18 Constitution saving throw against the damage. On a success, the target takes half as much damage and the damage can be resisted.

Shadow Swap. Zed swaps his location with that of a Living Shadow or blinks to an unoccupied area of dim light or darkness within 60ft of him.

Ninja Training. Zed can take the Dash, Disengage, or Hide action. Alternatively, Zed can make a Shadow Blade attack if he attacks as his action; this attack may add his dexterity modifier to the damage rolled.

Zed can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another creature's turn. Zed regains spent legendary actions at the start of his turn.

None Can Hide. Zed makes a Perception check.

Swift as Night. Zed moves up to half his speed without provoking opportunity attacks.

Seize Power. Zed attacks with Shadow Blade or Razor Shuriken (Only one Living Shadow can copy this attack).

Shadows Abound (Costs 2 Actions). Zed creates a new Living Shadow.

Enlightenment of the Shadows (Costs 3 Actions). Zed recharges Death Mark and adds +2 to his AC (until the start of his next turn).