Berov

Blessing of the Trickster. Berov has advantage on all Stealth checks.

MetaMagic. Berov is able to twist magic and the arcane at will, he has access to 2 metamagic abilities and 2 sorcerer points which are regained upon a long rest. 

• Quickened Spell. When you cast a spell that has a casting time of 1 action, you can spend 2 sorcery points to change the casting time to 1 bonus action for this casting.

• Subtle Spell. When you cast a spell, you can spend 1 sorcery point to cast it without any somatic or verbal components.

Words of Terror. If Berov speaks to a humanoid alone for 1 minute, He can sow seeds of paranoia. At the end of the conversation, the target must make a DC17 wisdom saving throw or be frightened of a target of His choice. The target stays frightened for up to 1 hour, until it is attacked or damaged, or it see's it's allies being attacked or damaged.

Spellcasting. Berov is a 20th-level spellcaster. Its spellcasting ability is Wisdom and Charisma (spell save DC 17, +10 to hit with spell attacks). Berov has following Cleric and Bard spells prepared:
Cantrips (at will): Thaumaturgy, Light, Toll the Dead, Minor Illusion, Friends, Prestidigitation, Mage Hand
1st level (8 slots): Charm Person, Disguise Self, Command, Shield of Faith, Dissonant Whispers, Sleep
2nd level (6 slots): Silence, Spiritual Weapon, Detect Thoughts, Hold Person, Shatter, Mirror Image, Pass Without Trace
3rd level (6 slots): Spirit Guardians, Dispel Magic, Create Food and Water, Nondetection, Major Image, Blink
4th level (3 slots): Guardian of Faith, Divination, Freedom of Movement, Dimension Door, Polymorph
5th level (2 slots): Dominate Person, Modify Memory, Raise Dead, Geas
6th level (1 slot): Otherworldy Form, Harm
7th level (1 slot): Regenerate, Etherealness

Attack Action. When Berov makes a melee attack, he can attack once with each weapon. 

Greatclub Smash. Melee Weapon Attack: +9 to hit. Hit: 25 (1d8 Bludgeoning + 6d6 Psychic) damage. When Berov hits a creature with his greatclub he can choose to attempt to knock them prone or push them 5 ft in a direction, the target must suceed a DC 15 strength saving throw to avoid this.

Trunk Daggers. Melee Weapon Attack: +6 to hit. Hit: 2(1d4 Piercing) damage. When hit with the dagger the target must suceed a DC 14 Constitution save or take 2d8 poison damage and be poisoned for 1 minute

Invoke Duplicity. As an action, Berov creates a perfect illusion of himself that lasts for 1 minute, or until he loses your concentration . The illusion appears in an unoccupied space that he can see within 30 feet of him. As a bonus action on his turn, he can move the illusion up to 30 feet to a space he can see, but it must remain within 120 feet of him. For the duration, he can cast spells as though he were in the illusion's space, but he must use his own senses. Additionally, when both him and his illusion are within 5 feet of a creature that can see the illusion, he has advantage on attack rolls against that creature, given how distracting the illusion is to the target.

Cloak of Shadows. As a bonus action Berov can turn invisible until the beginning of the next turn, this invisiblity breaks if he makes an attack or casts a spell

Thulsa's Fang. Once per day as a bonus action, Berov can summon 1d4 Giant Constrictor Snakes, These last 10 minutes and when they die, or the duration ends, they turn to stone, and easily crumble when force is applied to them. 

Mantle of Whispers. When a humanoid dies within 30ft of Berov, He can use his reaction to magically capture their shadow. He can choose to use the shadow as an action, when he does, it vanishes, magically transforming into a disguise for Him. He now looks exactly like the dead person, but healthy and alive. He has access to any information that the humanoid would share casually with an acquaintance. Such as general details like background or personal life, but not secrets. Another creature can see through this disguise by succeeding on a Insight check contested by His Deception check. You gain a +5 bonus to your check. Once he captures a shadow with this ability He can't capture another until after a long or short rest. 

Legendary Resistance (2/Day). When Berov fails a saving throw, he can use a charge of Legendary Resistance to instead suceed. 

Grim Opposition. (1/Day). A black smog is emitted from Berov, and a sphere of magical darkness is emitted in a 30ft radius. Light can't enter it and without blindsight you can't see inside

Enter the description for how mythic actions work for your monster here.

Mythic Action Name (Costs # Actions). Enter the description for your mythic action.