Vecna

Vecna, the Maimed God, looking smug as shit.

Vecna (his name is an anagram of the last name of Jack Vance, the man who invented the "fire and forget" rules for magic used in non-4e D&D) is one of Evil deities in D&D, having become considerably more powerful over various editions. He also buttfucked reality itself, punking the major powers of Ravenloft, Greyhawk and Planescape in rapid succession so hard that it resulted in third edition, where fullcasters like him were overpowered beyond belief Just as Planned. Even after being beaten by the typical plucky band of adventurers, he still got a net gain in power from Demi-god to Lesser god, double Just as Planned. If there is a Doctor Doom equivalent in D&D, it is Vecna, fucker's the most intelligent being of mortal origin ever and unlike Asmodeus who constantly says he's all smart and wise and awesome but has seemingly accomplished precisely dick out of hell besides maintain the status quo, Vecna actually goes out and gets shit done and utterly buttfucked the status quo.

Genesis

Born in the human city of Fleeth, Vecna was taught magic by his mother Mazell. She taught him that the great serpent Mok'sylk taught the god-kings of the Ur-Flan (ancestors of a people living in modern Greyhawk) magic. This serpent is said to be one of the Ancient Bretheren, a group of powerful pre-deity beings that include such movers as Ahriman, Jazirian and the Lady of Pain. She taught the young Vecna that he was descended from the Ancient Bretheren and that it devoured all those who honored it in life. When the princess of the city requested a medicine from Mazell she prescribed one, but since the princess intentionally disregarded the dose she ODed and died. The city guard was ordered to kill Vecna in front of the woman as a retalliation, but Mazell used her magic to allow Vecna to escape. Not happy with this, the authorities dragged her to the public square and burned her alive. But as she died, the woman's soul was seemingly devoured by a great serpent. The young Vecna fled and continued his study of magic. He claimed to have been trained by the Serpent itself, but if this is actually true or part of the Lich's madness is unknown. Over a thousand years later, he had become a powerful lich and laid siege to Fleeth. Officials approached him and offered their lives if he'd spare the citizens. Instead, Vecna let his army murder everyone in the city BUT the officials.

As he began a ritual to ascend into godhood, Vecna was betrayed by Kas, his most trusted lieutenant. In a climactic battle that cost the lich his left eye and hand, Vecna reached apotheosis followed by an explosion that leveled the new god's empire and flung both of them across the planes.

Domain

Vecna is the Evil god of Undead, Necromancy and Secrets. Specialising in dark magics and undeath, he is the go-to guy for necromancers and dark mages of all sorts.

Profane Artifacts

Because of the fact that Vecna is supposed to be one scary evil motherfucker, and because he famously got bits of himself hacked off before he ascended to godhood, Vecna's Eye and Hand have long held a place in the game as epicly powerful evil magical items, which would usually fuck you over if you were actually stupid enough to use them - not least of all because, to actually wield them, you had to be willing to hack off your own left hand or gouge out one of your eyes first before you could put them on.

In the 2e adventure "Die, Vecna, Die!" it was stated that since Vecna was a lich first and a god second, many of his bodyparts were actually lost before Kas' betrayal or during that climatic fight, so that whilst Vecna's avatar shows no sign of their loss (they're just not as "resonant" to his personal mythos as his hand and eye), they can still be found and used for power. The adventure statted up no fewer than twelve other bits of his body as minor artifacts that 3rd edition collectively called "The Fragments of Vecna". These artifacts consisted of the First Digit (right thumb), Second Digit (right index finger), Third Digit (right middle finger), Last Digit (right pinky finger), Incisors (a pair of inappropriately named fang-like canines), Molar, Scalp, Skin, Heart, Foot (left), and Right Eye.

Naturally, this was so stupid that it was swiftly swept under the rug, for the most part. However, the final issue of Dragon Magazine, issue #359, featured rules for the "Left Ear of Vecna" as a minor artifact, whilst "Open Grave", a 4e sourcebook analogous to the Libris Mortis, features a female Vecna-worshipping lich named Osterneth who still possesses "the Heart of Vecna", which she keeps in her own chest.

The existence of the Hand and Eye, and perhaps to a lesser extent the Fragments, inspired one memetically famous joke artifact: the legendary Head of Vecna.

Other artifacts associated with Vecna without actually being part of him consist of the Sword of Kas, the Rod of the Whispered One, and a pair of books. The Compendium Maleficarum is a book of spells, doctrines, and secrets crafted entirely from bone (even the pages) and penned in blood, that is on par with the Fragments of Vecna. The Tome of Shared Secrets is an illustrated bestiary of relic status, with the ability to impart knowledge of dark and evil creatures at the cost of a portion the user's life force. Vecna is also credited as one of the authors who contributed to the Book of Vile Darkness, and indeed was the one that consolidated the contents of a collection of scrolls into THE actual book, complete with the, perhaps cliche, cover made of human flesh (specifically a face) and demon bones. Since that time copies have been published, most are shoddy knock offs that have spelling or grammar errors that drag readers into the Lower Planes.

Dwelling

Vecna has no permanent home, not in the Astral Sea, the Abyss, Shadowfell or anywhere else. He and his followers travel the planes in search of knowledge, artifacts and power. He always travels out of sight and in the dark to avoid attention, prefering forgotten libraries, ruins of lost civilisations, Shadowfell and the Planes. Vecna does hold strongholds in several locations, but they are either far away or well-hidden from civilisation, or are located in dangerous areas, such as Pandemonium.

Servants

Vecna has the desire to rule over all, living and dead. He is worshipped by all those who desire knowledge and that which is not meant to be known. Undead that are not in service to Orcus are almost always in service to the Maimed God. He commands all sorts of undead, from run-of-the-mill zombies and skeletons to Oni, Liches, Vampires and various kinds of constructs. His followers often band together in cults, dedicated to the practice of necromancy, finding secret knowledge, or both. These cults build their own altars and places of worship to their lord.

There are some who stand out in service to (or against!) their lord:

• Acererak is the Demilich in charge of the Tomb of Horrors. Only his head is in the Tomb though (or more specifically, a copy of his head). The rest of him is in Shadowfell, working on a spell to control undead everywhere.
• Osterneth appears as an attractive woman in her late 20s, but is actually a lich, bearing Vecna's heart in her chest, and is one of Vecna's most trusted allies.
• Kas the Betrayer is a vampire lord that schemes against Vecna. He was the one to maim the Maimed god, in an attempt to attain divinity himself. His weapon, the Sword of Kas, roams the planes and is the only weapon believed to be able to kill Vecna.