Legendary Resistance (5/Day). If Vecna fails a saving throw, he can choose to succeed instead.

Special Equipment. Vecna carries a magic dagger named Afterthought. In the hands of anyone other than Vecna, Afterthought is a +2 Dagger.

Undying. If Vecna is slain, his soul refuses to accept its fate and lives on as a disembodied spirit that fashions a new body for itself after 1d100 years. Vecna’s new body appears within 100 miles of where he was slain. When the new body is complete, Vecna regains all his hit points and becomes active again.

Undead Calling. If Vecna's Legendary Resistance trait has activated in the last hour, Vecna can call any one undead creature to be his servant, and when the undead creature is summoned and entered into combat, the undead creature is after Vecna in initiative.

Multiattack. Vecna uses Flight of the Damned (if available), Rotten Fate, or Spellcasting. He then makes two attacks with Afterthought.

Afterthought. Melee Weapon Attack: +13 to hit, reach 5 ft., one target. Hit: 7 (1d4 + 5) piercing damage plus 9 (2d8) necrotic damage. If the target is a creature, it is afflicted by entropic magic, taking 9 (2d8) necrotic damage at the start of each of its turns. Immediately after taking this damage on its turn, the target must make a DC 20 Constitution saving throw, ending the effect on itself on a success. Until it succeeds on this save, the afflicted target can’t regain hit points.

Flight of the Damned (Recharge 5–6). Vecna conjures a torrent of flying, spectral entities that fill a 120-foot cone and pass through all creatures in that area before dissipating. Each creature in that area must make a DC 22 Constitution saving throw. On a failed save, the creature takes 36 (8d8) necrotic damage and has the frightened condition for 1 minute. On a successful save, the creature takes half as much damage. A frightened creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.

Rotten Fate. Vecna causes necrotic magic to engulf one creature he can see within 120 feet of himself. The target must make a DC 22 Constitution saving throw, taking 96 (8d8 + 60) necrotic damage on a failed save or half as much damage on a successful one. A Humanoid killed by this magic rises as a zombie at the start of Vecna’s next turn and acts immediately after Vecna in the initiative order. The zombie is under Vecna’s control.

Spellcasting. Vecna casts one of the following spells, requiring no material components and using Intelligence as the spellcasting ability (spell save DC 22):

At will: Animate Dead (as an action), Detect Magic, Dispel Magic, Fly, Lightning Bolt, Mage Hand, Prestidigitation

2/day each: Dimension Door, Invisibility, Scrying (as an action)

1/day each: Dominate Monster, Globe of Invulnerability, Plane Shift (self only)

Vile Teleport. Vecna teleports, along with any equipment he is wearing or carrying, up to 30 feet to an unoccupied space he can see. He can cause each creature of his choice within 15 feet of his destination space to take 10 (3d6) psychic damage. If at least one creature takes this damage, Vecna regains 80 hit points.

Corruption (Recharge 6). When used, on the turn of whoever holds the Eye or/and hand of Vecna, Vecna takes full control over the possessor's turn, along with the possessor of the items to take 9 (2d8) necrotic damage.

Vecna can take up to three reactions per round, but only one per turn.

Dread Counterspell. Vecna utters a dread word to interrupt a creature he can see that is casting a spell. If the spell is 4th level or lower, it fails and has no effect. If the spell is 5th level or higher, Vecna makes an Intelligence check (DC 10 plus the spell’s level). On a successful check, the spell fails and has no effect. Whatever the spell’s level, the caster takes 10 (3d6) psychic damage if the spell fails.

Fell Rebuke. In response to being hit by an attack, Vecna utters a fell word, dealing 10 (3d6) necrotic damage to the attacker, and Vecna teleports, along with any equipment he is wearing or carrying, up to 30 feet to an unoccupied space he can see.

Legendary Action Uses: 3. Immediately after another creature's turn, Vecna can expend a use to take one of the following actions. Vecna regains all expended uses at the start of each of their turns.

At-Will Spell. Vecna casts one of his at-will spells.

Disrupt Life (Costs 3 Actions). Each creature within 20 feet of Vecna must make a DC 20 Constitution saving throw against this magic, taking 42 (12d6) necrotic damage on a failed save, or half as much damage on a successful one.

Donjon Visit (Costs 2 Actions). One Huge or smaller creature that Vecna can see within 60 feet of it must succeed on a DC 19 Charisma saving throw or be teleported to an unoccupied space on the floor of the Demiplanar Donjon. At the end of the target's next turn, it reappears in the space it left or in the nearest unoccupied space if that space is occupied.

Psychic Projection (Costs 3 Actions). Each creature within 60 feet of Vecna must make a DC 19 Wisdom saving throw, taking 26 (4d10 + 4) psychic damage on a failed save, or half as much damage on a successful one.

If Vecna's Legendary Resistance trait has activated in the last hour, it can use the options below as legendary actions.

Necrotic Counterspell. Vecna casts counterspell at will, and the target and all creatures within a 10-foot radius take 10 (3d6) necrotic damage and are prone.

Over Donjon Visit. Three medium-sized creatures that Vecna can see within 60 feet of it must succeed on a DC 19 Charisma saving throw or be teleported to an unoccupied space on the floor of the Demiplanar Donjon. At the end of the target's next turn, it reappears in the space it left or in the nearest unoccupied space if that space is occupied.