Medium undead (lich, wizard), lawful evil

Armor Class: 20 (mystic armor)

Hit Points: 285 (30d8 + 150)

Speed: 30 ft , fly: 60 ft , can hover

STR

14 +2

DEX

17 +3

CON

20 +5

INT

25 +7

WIS

23 +6

CHA

18 +4

Saving Throws: CON +13, INT +15, WIS +14

Skills: Arcana +23, Deception +12, History +15, Insight +14, Investigation +15, Perception +14, Stealth +11

Damage Resistances: Cold, Lightning, Necrotic

Damage Immunities: Poison; Bludgeoning, Piercing, and Slashing from Nonmagical Attacks

Condition Immunities: Charmed, Dazed, Exhaustion, Frightened, Paralyzed, Poisoned, Stunned

Senses: Truesight 120 ft., Passive Perception 24

Languages: Abyssal, Celestial, Common, Deep Speech, Draconic, Elvish, Giant, Infernal, Minotaur, Telepathy 300 ft., Undercommon

Challenge Rating: 27 ( 105,000 XP)

Proficiency Bonus: +8

Actions

Epic Actions. On his turn, Nexarion can use its bonus action, movement, and interaction as normal. However, he does not take an action on its turn unless forced to do so by a spell or other effect.   Staff of Dominion. Melee Weapon Attack: +13 to hit, reach 5 ft., one target. Hit: 9 (1d8 + 5) bludgeoning damage plus 17 (5d6) necrotic damage. The target must succeed on a DC 20 Constitution saving throw or have their magical energy drained, losing access to one spell slot of the highest level they have available (maximum 8th-level).     Weave Shatter (Recharge 5–6). Nexarion unleashes a wave of destructive energy that rips through the fabric of magic itself in a 60-foot cone. Each creature in the area must make a DC 26 Dexterity saving throw, taking 45 (10d8) force damage on a failed save, or half as much damage on a successful one. Creatures failing the save by 5 or more are also stunned for 1 minute. They can make a DC 26 Constitution saving throw at the end of each of their turns, ending the stunned condition on a success.   Decree of Necrosis. Nexarion targets one creature he can see within 120 feet. The target must succeed on a DC 26 Constitution saving throw or take 110 (10d10 + 50) necrotic damage. A humanoid slain by this spell rises as a wight under Nexarion’s control until dismissed or slain.   Spellcasting. Nexarion casts one of the following spells as a 20th-level spellcaster, using Intelligence as his spellcasting ability (spell save DC 26, +18 to hit with spell attacks):   Cantrips (at will): chill touch, mage hand, message, minor illusion, prestidigitation   At will (minimum 2nd-level): detect magic, feather fall, identify, hold person, magic missile, mirror image, scrying, see invisibility, sleep   3/day each (5th-level): animate dead, banishment, dimension door, dispel magic, dominate person, fireball, gaseous form, greater invisibility, hypnotic pattern, magic missile, polymorph, seeming, wall of force   2/day each (7th-level)): disintegrate, eyebite, finger of death, forcecage, globe of invulnerability, magic missile, mass suggestion, project image, teleport   1/day each(9th-level): dominate monster, feeblemind, foresight, magic missile, mind blank, power word kill, power word stun, time stop

Bonus Actions

Arcane Shift. Nexarion teleports up to 120 feet to an unoccupied space he can see. Each creature within 5 feet of the space he left must succeed on a DC 23 Wisdom saving throw or be frightened until the end of Nexarion’s next turn.

Reactions

Arcane Retaliation. In response to being hit by an attack, Nexarion can cause the attacker to make a DC 26 Intelligence saving throw. On a failure, the attacker takes 21 (6d6) force damage and is pushed 20 feet away.   Spell Parry. Nexarion uses his staff to deflect a spell targeting him. He makes an Intelligence check (DC 10 + the spell's level). On a success, the spell fails and has no effect, but any spell slots or charges are not wasted, and the caster of the spell takes psychic damage equal to a number of d4s equal to 1 + the spell slot level of the spell countered.   Ultimate Contingency (1/Day). When targeted by an attack or spell, or included in the area of the spell, Nexarion can cast any spell on the wizard spell list without any components, interrupting (and potentially avoiding) the triggering effect. The spell’s normal casting time changes to 1 reaction.

Legendary Actions

Nexarion can take a number of legendary actions equal to the number of player characters in the initiative order, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another player character's turn. Nexarion regains spend legendary actions at the start of a new round of combat. Attack (Costs 1 Legendary Action). Nexarion makes two attacks with his Staff of Dominion.   Decree of Necrosis (Costs 1 Legendary Action). Nexarion uses his Decree of Necrosis ability.   Spell (Costs 1 Legendary Action). Nexarion casts a spell of 5th level or lower.   Weave Shatter (Costs 1 Legendary Action). Nexarion uses his Weaver Shatter ability, if available.   Arcane Master (Costs 2 Legendary Actions). Nexarion casts a spell of 6th level or higher.

Lair Actions

When fighting within his lair, Nexarion can manipulate the environment to his advantage. On initiative count 20 (losing initiative ties), Nexarion can take a lair action to cause one of the following effects:

• Necrotic Pulse: Nexarion releases a pulse of dark energy. Each creature of his choice within 60 feet must make a DC 18 Constitution saving throw, taking 4d6 necrotic damage on a failed save, or half as much damage on a successful one.
• Shadow Step: Nexarion teleports up to 60 feet to an unoccupied space that he can see within his lair. Additionally, shadows cloak him, giving him advantage on stealth checks until the start of his next turn.
• Arcane Lockdown: Doors within the lair magically lock or unlock, traps are activated or deactivated, and barriers of magical force spring up or dissipate at Nexarion’s command.

Nexarion’s lair, the Sanctum of Shadows, is situated deep beneath the capital city of Velora, accessible only through a series of hidden passages and protected by powerful magical wards and traps. The lair is carved out of ancient, dark stone and is alive with pulsating arcane energy.   The atmosphere of the sanctum is oppressive and eerie, filled with the whispers of the past and the weight of eternal darkness. Flickering torches with magical flames that never extinguish light the winding corridors and vast chambers, casting long shadows.

Regional Effects

The region containing Nexarion’s lair is twisted by his magic, creating the following effects:

• Suppressed Light: Natural light within one mile of the lair is dimmed, as if under the effect of a perpetual twilight, and magical light sources are halved in radius.
• Whispers of the Arcane: Residents near the lair occasionally hear whispers that tempt them with promises of power and knowledge. This can result in an increase in magical study but also a higher incidence of madness.
• Undead Stirrings: Undead creatures within 5 miles of the lair become more active and are drawn towards the lair. They act with a semblance of purpose, as if guided by Nexarion’s will.