Chancellor Alberio Vex

Spectral Mind.  Alberio can manifest a spectral mind up to 300 ft away from him. The spectral mind (and Alberuo through the mind) can hear and see and has darkvision with a range of 60 feet. Alberio can cast spells from the Spectral Mind's space up to 8 times per long rest.

One with the Word. Alberio makes all arcana checks with advantage.

Nondetectable. Alberio cannot be detected with divination magic. Any magical attempts to spy on him or learn his lore or abilities fail and the caster must make a DC 23 Arcana or Stealth check (they choose) or Alberio will know they tried to spy.

Spellbook. Chancellor Vex can cast any of these spells as a ritual using the spell's normal casting time.

1st level: alarm, ceremony, comprehend languages, detect magic, detect poison and disease, floating disk, identify, illusory script, purify food and drink, speak with animals, unseen servant

2nd level: animal messenger, augury, beast sense, locate animals or plants, magic mouth, silence, skywrite

3rd level: feign death, Leomund's Tiny Hut, phantom steed, water breathing, water walk

4th level: divination

5th level: commune with nature, Rary's telepathic bond

6th level (2 slots): Drawmij's instant summons, forbiddance

War Caster. Chancellor Vex has advantage on concentration checks and can cast spells as opportunity attacks.

Metamagic Adept. Vex has two sourcery points and can spend one sorcery point to double a spell's duration or one point to cast the spell without verbal or somatic components.

Mage Slayer. When Chancellor Vex damages a creature that is concentrating on a spell, that creature has disadvantage on the concentration check, and Alberio has advantage on saving throws against spells cast by creatures within 5 feet.

Spellcasting. Chancellor Vex is a 20th level wizard. His spellcasting ability is Intelligence (spell save DC 23, +15 to hit with spell attacks). He can cast detect thoughts and darkness at will and has following spells prepared:

Cantrips (at will): mending, mage hand, minor illusion, mind sliver, prestidigitation

1st level (4 slots): cause fear,  expeditious retreat, mage armor

2nd level (3 slots): hold person, misty step, mirror image, Nystul’s magic aura, Tasha's mind whip

3rd level (5 slots): catnap, counterspell, dispel magic, glyph of warding, sending

4th level (3 slots): fabricate, locate creature otiluke's resilient sphere, phantasmal killer,

5th level (3 slots): Bigby's hand, legend lore, modify memory, synaptic static, telekinesis

6th level (2 slots): contingency, mental prison, soul cage

7th level (2 slots): forcecage, symbol, teleport

8th level (1 slot): demiplane, mind blank

9th level (1 slot): imprisonment, time stop

Dagger. Melee Weapon Attack: [rollable]+3 to hit, reach 5 ft., one target. Hit: 1d4 +3

Telekinetic. As a bonus action, Alberio can try to telekinetically shove a creature within 30 feet of you. The target must succeed on a DC 23 Strength saving throw or be moved 5 feet toward or from Vex.

Mage Slayer. When a creature within 5 feet of Alberio casts a spell, he can use his reaction to attack that creature.