Vecna

Vecna, also known as the Whispered One, the Undying King, and the Lord of the Rotted Tower, was a powerful, mortal-born archlich who achieved godhood.

The plot of Chapter 3 was based around the Briarwoods' attempt to complete a ritual for Vecna in the Ziggurat beneath Whitestone. For a while, it seemed that Vox Machina managed to stop this ritual in time.

However, in Chapter 8, Delilah Briarwood returned with a cult known as the Remnants, who worshipped Vecna and sought to resurrect him. Delilah made a second, more successful, attempt at her ritual for Vecna, and it became apparent that her first was more successful than it had seemed.

Vecna was resurrected and ascended to godhood through a ritual of seeding in. He was the most powerful enemy Vox Machina ever faced, but Keyleth successfully banished him from the Prime Material Plane in.

Background
Upon cheating death, Vecna began searching for ways to turn himself into a god, but his ritual was thwarted and he himself was slain six hundred years before the time of Vox Machina. Vecna was later considered a lesser deity or "patron saint" of dark, coveted secrets, and this belief and worship lent him new power.

When Vox Machina interrogated Riskel Daxio after disrupting the Briarwoods' ritual, Riskel revealed that he would be reborn, that he is the blood of Vecna, and that other parts of Vecna are "everywhere". Although he did not know the purpose of the Sphere of Annihilation beneath Whitestone, Riskel explained that his deal with Vecna would provide him "power through not knowing", and the fact that Vecna kept his followers in the dark meant that he trusted them.

Riskel also explained that the Briarwoods' ritual was part of the same effort that had been attempted before, implying that this was another attempt to turn Vecna into a god. Since Riskel wasn't present for the Briarwoods' attempt, he wasn't sure if it was successful or not.

While searching the former house of General Krieg, Vox Machina kept a cautious eye out for any references to Vecna. Pike took the time to look for religious iconography that might be related to Vecna, and when they found a series of busts depicting J'mon Sa Ord, Vex suspected they might be related to the "god of secrets" since Riskel Daxio was planning to flee to Ank'Harel. Suspicions were further aroused when they found a humanoid skull with a gem in one of the sockets, but their worries subsided slightly when it was seen that the gem was in the right eye socket.

Vex, still on the look out for signs after the Chroma Conclave attacked, asked Osysa if she knew anything about Vecna. Osysa reacted violently at the mention of his name, stating that he was one of the few forces capable of limiting her sight. After Percy told her of the attempted ritual beneath Whitestone she scried to the location and revealed that the Ziggurats were originally built as temples for Ioun, but were taken and corrupted by Vecna and his followers.

After receiving information from Scanlan and Lionel of a second Ziggurat within the Smolder Crown mountain range, in the deserts of Marquet, Vox Machina set out to investigate and defeat the cult that had taken residence there.

Upon reaching the heart of the Ziggurat, where the pyramid's Orb of Annihilation was located, Vox Machina found the cult and its leader...who turned out to be the supposedly deceased Lady Delilah Briarwood. After a fierce battle with the aid of her cultists, Delilah retreated by traveling through the Orb to the Shadowfell beyond.

Pike cast "Speak with Dead" on one of the deceased cultists. The cultist revealed that one can only pass safely through the Orb using specially crafted stones, one of which Delilah carried. The cultist revealed that his group was one of the Remnants, who serve "the Undying King": Vecna. When asked how Delilah was able to return, the cultist simply replied, "I know not the means, but she is a powerful necromancer." Vox Machina speculated that she was able to avert her death with some kind of preventative spell that she had prepared before the fight in Whitestone. As the spell faded, the party was left to contemplate the cultist's last words: "His return is nigh. The Whispered One will come."

Vecna makes a brief, non-corporeal appearance in this episode where he launches a surprise attack on Sprigg's house, wounding the Gnome. It is implied that Vecna has some connection to Sprigg, but that connection (as of now) remains unknown.

While Vox Machina is talking with the Goddess Ioun she senses Vecna's ascension.

Vecna, using his undead Earth Titan thrall, laid siege to Vasselheim. As the Dawn City fought to defend itself, Vecna battled with Vox Machina atop the Tower of Entropis. Vecna used his magic to shatter the tower and levitate the remains, forcing Vox Machina to fight among the floating "islands".

After a fierce battle, Vecna was weakened enough that three wounds appeared on his body: one in his shoulder, one in his chest, and one on the side of his head. Though the Raven Queen's trammel shattered upon attempting to thrust it into the lich-god, Grog succeeded in fusing the remaining two trammels into Vecna. Keyleth then read the ritual from the Tome of Isolation, and Vecna's divine form was forced out of the Prime Material Plane to a plane beyond the Divine Gate: permanently sealed away.

Known Followers

 * Lady Delilah Briarwood
 * Lord Sylas Briarwood
 * Lord Riskel Daxio
 * Professor Anders

Abilities

 * The Hand of Vecna granted Vecna many benefits while he was attuned to it. These included:
 * Strength score increased to 20 (unless it was already higher than 20)
 * Melee spell attacks cast with and melee weapon attacks made using the Hand of Vecna deal an extra 2d8 cold damage.
 * The Hand had a number of charges (exact number unknown) that enabled Vecna to cast spells with it. These included:
 * Finger of Death
 * Teleport

Wizard Spells
As a deity, Vecna had the ability to cast high level spells more often than any mortal wizard could hope to achieve. Notably, he had three 9th-level spell slots, whereas the maximum for player characters is one.

Cantrips

 * Fire Bolt

3rd-level

 * Counterspell
 * Dispel Magic
 * Fireball

4th-level

 * Banishment
 * Polymorph

5th-level

 * Dominate Person
 * Hold Monster
 * Telekinesis

6th-level

 * Circle of Death
 * Disintegrate

7th-level

 * Finger of Death
 * Forcecage

8th-level

 * Feeblemind
 * Maze

9th-level

 * Meteor Swarm
 * Power Word Kill
 * Gate

Notable Items

 * Hand of Vecna (grafted to the left arm of Arkhan the Cruel)

Quotations

 * "I can help you." (Vecna's first words to Delilah Briarwood)
 * "I can give you the secret to bring your love back to life...but then you owe me. You're mine." (Vecna offering the Rites of Vampirism in exchange for the service of the Briarwoods)
 * "Sleep."
 * "Don't worry: if you love her that much, I'll send her to you."
 * "No...No! Too long!  TOO LONG!!  TOOOOO LOOOONG!!!" (final words before being banished)

Trivia

 * Because Vecna is a licensed character, he is never mentioned in the Tal'Dorei campaign guide by name (along with all the deities). Instead he is referred to exclusively by his most popular title, "The Whispered One".
 * The Ritual of Isolation did not kill or destroy Vecna, but rather it forced his divine form to another plane on the opposite side of the Divine Gate. It is unknown which of the Outer Planes that Vecna was banished to, but it is assumed to be one of the planes of the Betrayer Gods.  Based on Vecna's alignment (Neutral Evil), it is likely Carceri, The Gray Waste, or Gehenna.
 * The miniature used for Vecna on the battle map was a conversion of the Warhammer Fantasy End Times model for Nagash., a curious fact considering the various similarities between the two characters, both being powerful necromancers that achieved lichdom and godhood