Merrun is a 8th-level spellcaster. Her spellcasting ability is Charisma (spell save DC 21, +13 to hit with spell attacks). Merrun has the following spells prepared:
1st level (4 slots): Shield, Unseen Servant, Magic Missle
2nd level (3 slots): Borrowed Knowledge Mirror Image, Misty Step
3rd level (3 slots): Counterspell, Dispel Magic, Sending
4th level (2 slots): Greater Invisibility
Devils Sight. Magical darkness doesn't impede Merrun's darkvision.
Immutable Form. Merrun is immune to any spell or effect that would alter her form.
Legendary Resistance (2/Day). If Merrun fails a saving throw, she can choose to succeed instead.
Magic Weapons. Merruns's weapon attacks are magical.
Vampiric Aura. At the start of each of Merrun's turns, each creature within 5 feet of her takes 5 2d10 necrotic damage. A creature that touches Merrun or hits her with a melee attack while within 5 feet of her takes 5 2d10 necrotic damage.
Multiattack. Merrun makes 3 attacks, two weapon attacks, and one Bite attack. She can use her Claws instead of her Bite.
Bite. Melee Weapon Attack: d20+11 to hit, reach 5 ft., one target. Hit: 8 2d6+5 magical piercing damage. If the target is a creature, Merrun regains the damage as health.
Claws. Melee Weapon Attack: d20+8 to hit, reach 5 ft., one target. Hit: 8 d6+2 magical slashing damage.
Forsaken Brand. Melee Weapon Attack: d20+11 to hit, reach 5 ft,. one target. Hit: 9 1d8+5 magical slashing damage plus 18 4d8 necrotic damage and if the target is a creature, it can't regain hit points until the start of Merrun's next turn.
Forsaken Arrow. Ranged Weapon Attack: d20+15 to hit, range 150/600 ft., one target. Hit: 10 2d8+6 piercing damage plus 18 6d8 necrotic damage. If the target is a creature, it can't regain hit points until the start of Merrun's next turn.
Children of Blood (1/Day). Merrun magically calls 3d6 Imps. While outdoors, Merrun can call 2d4 Hellwasps instead. The called creatures arrive in 1d4 rounds, acting as allies of Merrun and obeying her spoken commands. The creatures remain for 1 hour, until Merrun dies, or until Merrun dismisses them as a bonus action.
Merrun 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. Merrun regains spent legendary actions at the start of her turn.
Move. Merrun moves up to her speed without provoking opportunity attacks.
Claws. Merrun makes a Claw attack.
Forsaken brank. Merrun makes a Forsaken Brand attack.