Antilia, Daughter of Mephistopheles

Bardic Inspiration (6/day). As a bonus action, Antilia chooses another creature that can see or hear her within 120 feet. That creature gains a bardic inspiration die if it does not already have one, a d12. Before 10 minutes pass, the creature can expend the die to add its result to an attack roll or saving throw.  After doing so, it has advantage on all attack rolls and saving throws for the next minute.

Devil’s Sight. Magical darkness doesn’t impede Antilia’s darkvision.

Fey Ancestry. Antilia has advantage on saving throws against being charmed and magic can’t put her to sleep.

Fiendish Blessing. The AC of Antilia includes her Charisma bonus.

Innate Spellcasting. Antilia’s spellcasting ability is Charisma (spell save DC 21). Antilia can innately cast the following spells, requiring no material components:

3/day: detect magic

1/day each: burning hands, flaming sphere, plane shift (self only)

Spell Leech. As a bonus action, Antilia chooses one ally she can see within 30 feet of it. The target loses its lowest-level spell slot, and Antilia gains it.

Spell Shield. Antilia has advantage on saving throws against spells. If she succeeds on such a saving throw, she gains temporary hit points equal to the spell's level.

Spellcasting. Antilia is a 20th level spellcaster. Her spellcasting ability is Charisma (spell save DC 21, +13 to hit with spell attacks). Antilia knows the following bard spells:

Cantrips (at will): fire bolt, mage hand, prestidigitation, vicious mockery

1st level (4 slots): charm person, cure wounds, healing word, sleep thunderwave

2nd level (3 slots): flame blade, silence

3rd level (3 slots): fear, fireball

4th level (3 slots): compulsion, greater invisibility

5th level (3 slots): dream, hold monster, legend lore

6th level (2 slots): mass suggestion

7th level (2 slots): mirage arcane, project image, regenerate

8th level (1 slot): glibness

9th level (1 slot): foresight, power word kill, true polymorph

Multiattack. Antilia makes two melee attacks or uses her Fire Ray twice.

Rapier. Melee Weapon Attack: +14 to hit, reach 5 ft., one target. Hit: 11 (1d8 + 7) piercing damage plus 3 (1d6) fire damage.

Fire Ray. Ranged Spell Attack: +13 to hit, range 120 ft., one target. Hit: 10 (3d6) fire damage.