Corrupted Jester

Legendary Resistance. (3/day)When it rolls an attack role, ability check and saving throw, it can use a legendary resistance to roll additional d20 after learning of the result.

Magical Resistance. The Jester rolls with advantage against saving throws from spells, and magical effects.

Ventriloquism. The jester can project its voice and noise from any of its equipment at any location 60 feet from its position.

Imbuing Darkness. While in Darkness or dim light, the Jester gains a + 5 to there AC. Additionally it gains resistance to all magical bludgeoning, piercing and slashing damage. It also gains the benefits of Evasion.

Evasion. When the Jester is in Darkness or dim light and makes a Dexterity saving throw, it takes no damage on a success, half the damage on a failure.

Light Sensitivity. If the jester is in bright or dim light, it has vulnerability to magical bludgeoning, piercing, slashing, and radiant damage.                               

Multiattack. The Jester uses Corrupting Claw attack, and then uses Twisted Vision or uses spellcasting.

Corrupting Claw. Melee Weapon Attack: + 12 to hit, reach 10 ft., one target. Hit: 12 (1d10 + 7) force damage, plus (6d10) necrotic damage if the jester is in darkness or dim light, half of the necrotic damage reduces maximum hit points.

Twisted Illusion. The jester targets a creature it can see 60 feet from it. The target must make DC 21 saving throw or be charmed for 1 minute. While being charmed, the creature can re roll its saving throw if its attacked by the Jester. If the creature succeeds the saving throw, it is immune to twisted vision for 24 hours.

Spellcasting. The Jester cast one of the following spells, requiring to material components and using Charisma as the spellcasting ability (spell save DC 21):

At will: Crown of Madness, Tasha's Mind Whip

2/day Confusion, Hypnotic Pattern

Shadow Step. The Jester erupts in black flames in a 5 foot radius that deals (1d10) necrotic damage to anyone in the radius. It then teleports to any point in darkness or dim light 120 feet from it.

The jester has 3 legendary actions, it can only use 1 option bellow at a time and it can only take a legendary action after a player turn. The Jester regains its legendary actions at the beginning of its turn. 

Confusing Guidance. The Jester uses Twisted Illusion. Alternatively it can choose a creature that is charmed by it, it must make a DC 21 Charisma saving throw, on a failure the jester choses what the creature acts on its next turn.

Dash. The Jester can use the dash action without provoking any attack of opportunities, and leaves a trail of darkness that disapears at the end of his next turn.

Spellcasting. The Jester cast a spell from its spell list.

Corrupting Claw (2 actions). The Jester uses a Corrupting Claw attack.