All Seeing Eye Assassin

Multiattack. The assassin makes three attacks, using Shortsword or Hand Crossbow in any combination.

Shortsword. Melee Weapon Attack: +9 to hit, range 5 ft. Hit: 12 (2d6 + 5) Slashing damage, plus 4 (1d8) Radiant damage, or 19 (4d6 + 5) Slashing damage plus 9 (2d8) Radiant damage if the attack was made with Advantage.

Hand Crossbow. Ranged Attack Roll: +9, range 30/120 ft. Hit: 12 (2d6 + 5) Piercing damage, plus 4 (1d8) Radiant damage, or 13 (2d8 + 4) Piercing damage plus 7 (2d6) Radiant damage if the attack was made with Advantage.

Spellcasting. The assassin casts one of the following spells, requiring no Verbal components, and using Wisdom as the spellcasting ability (spell save DC 16):

At Will: Detect Evil and Good, Detect Magic, Disguise Self, Find Traps, Guidance, Light, Thaumaturgy
2/Day Each: Blindness/Deafness, Calm Emotions, Charm Person, Command (level 3 version), Feign Death, Invisibility, Mirror Image, Pass Without Trace
1/Day Each: Blink, Confusion, Dimension Door, Dispel Magic, Hypnotic Pattern, Nondetection, Spirit Guardians

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

Invoke Duplicity (2/Day). The assassin creates an illusion of itself in an unoccupied space it can see within 30 feet. The illusion is intangible, doesn’t occupy its space, and lasts for 1 minute. The illusion ends early if the assassin dismisses it (no action required) or has the Incapacitated condition. The assassin can cast spells from the illusion's space, and can use this Bonus Action again to move the illusion up to 30 feet. Additionally, while the assassin and the illusion are within 5 feet of a creature that can see the illusion, the assassin has Advantage on attack rolls against that creature.

Mountebank's Magic (3/Day). The assassin casts Misty Step, Healing Word, or Spiritual Weapon, requiring no Verbal components, and using the same spellcasting ability as Spellcasting.

Trickster's Blessing. The assassin targets a willing creature it can see within 30 feet. The creature gains Advantage on Dexterity (Stealth) checks until it finishes a Long Rest or the assassin uses this Bonus Action again.

Vexing Attacker. Constitution Saving Throw: DC 16, one creature the assassin has hit with an attack roll in the last turn. Failure: The target has the Poisoned condition until the end of the assassin's next turn.

Skirmisher. Trigger: An enemy ends its turn within 5 feet of the assassin. Response: The assassin moves up to half its Speed without provoking Opportunity Attacks.

Uncanny Dodge. Trigger: The assassin is hit by an attack roll. Response: The assassin halves the damage (round down) it takes from that attack.