Fey Ancestry. Quenthel has advantage on saving throws against being charmed, and magic can't put the drow to sleep.
Sunlight Sensitivity. While in sunlight, Quenthel has disadvantage on attack rolls, as well as on Wisdom (Perception) checks that rely on sight.
Special Equipment. Quenthel wields a tentacle rod.
Innate Spellcasting. Quenthel's spellcasting ability is Charisma (spell save DC 19). She can innately cast the following spells, requiring no material components:
At will: dancing lights
1/day each: darkness, faerie fire, levitate (self only)
Spellcasting. Quenthel is a 20th-level spellcaster. Her spellcasting ability is Wisdom (save DC 20, +12 to hit with spell attacks). Quenthel can cast any cleric spell up to 9th level at will.
Multiattack. Quenthel makes three tentacle rod attacks.
Scourge. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit:5 (1d6 + 2) piercing damage plus 17 (5d6) poison damage.
Summon Demon (1/Day). Quenthel attempts to magically summon a yochlol with a 30% chance of success. If the attempt fails, the drow takes 5 (1d10) psychic damage. Otherwise, the summoned demon appears in an unoccupied space within 60 feet of its summoner, acts as an ally of its summoner, and can't summon other demons. It remains for 10 minutes, until it or its summoner dies, or until its summoner dismisses it as an action.
Tentacle Rod. Melee Weapon Attack: +9 to hit, reach 5 ft., one target. Hit:5 (1d6 + 2) piercing damage. If she hits a target with all three tentacles, it must make a DC 15 Constitution saving throw. On a failure, the creature's speed is halved, it has disadvantage on Dexterity saving throws, and it can't use reactions for 1 minute. Moreover, on each of its turns, it can take either an action or a bonus action, but not both. At the end of each of its turns, it can repeat the saving throw, ending the effect on itself on a success.
Throne Activation. While seated on her throne, Quenthel can use an action on her turn to cast disintegrate (save DC 19). A target that fails its saving throw takes 10d6 + 40 force damage. If this damage reduces the target to 0 hit points, it is disintegrated.