Cunning Action. On each of its turns, the Master of Tricks can use a bonus action to take the Dash, Disengage, or Hide action.

Evasion. If the Master of Tricks is subjected to an effect that allows it to make a Dexterity saving throw to take only half damage, the Master of Tricks instead takes no damage if it succeeds on the saving throw, and only half damage if it fails.

Sneak Attack. Once per turn, the Master of Tricks 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 Master of Tricks that isn't incapacitated and the Master of Tricks doesn't have disadvantage on the attack roll.

Spellcasting. The Master of Tricks is a 15th level spellcaster.  It's spellcasting ability is Intelligence (spell save DC 14, +6 to hit with spell attacks). The Master of Tricks knows the following wizard spells:

Cantrips (at will): mage hand, prestidigitation, minor illusion, mind sliver

1st level (4 slots): disguise self, silent image, sleep, mage armor, 

2nd level (3 slots): darkness, shadow blade, mirror image, invisibility

3rd level (2): counterspell, major image

Shadow Blade. Melee or Ranged Weapon Attack: +8 to hit, reach 5 ft. or range 20/60 ft., one target. Hit: 9 (2d8) psychic damage.

Uncanny Dodge. The Master of Tricks halves the damage that it takes from an attack that hits it. The trickster must be able to see the attacker.

The Master of Tricks 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.The Master of Tricks regains spent legendary actions at the start of his turn.

Slip Away. The Master of Tricks moves up to its speed. This movement does not provoke opportunity attacks.

Cantrip. The Master of Tricks casts a cantrip.

Strike (Costs 2 Actions). The Master of Tricks makes one attack with its shadow blade.