Kyristan

Kyristan, also known as the Dead King, was a planewalking lich and author of magical tomes. His works included Kyristan's Mysteries and Studies in Death.

History
Kyristan was born on a world other than Toril.

At some point, Kyristan joined the wizard's guild of fellow planewalker Dar Malson, situated in the town of Northbank. Due to his expertise and power, he was able to ascend the ranks and become guildmaster in a short amount of time. His leadership was successful, but his power and magical prowess eventually led him to the path of lichdom.

In his studies, Kyristan invented several spells and, by experimenting on fellow guild members, first created what he called spectral wizards, a new kind of undead.

After successfully turning himself into a lich, Kyristan's ambitions shifted towards the creation of an army of undead. Around the, his plot to change a large group of wizards into spectral wizards was foiled, in part by Dar Malson.

Around the, Kyristan's Mysteries was stolen from the Lark in Suzail. The thief was found dead and questioned by the mage, confiding that he stole the book on orders from a "wealthy and handsome man". The Lark theorized that this employer was Kyristan himself, and that the thief successfully returned the book to its author, but other sages contested that both Kyristan's and the book's whereabouts were unknown at that point in time.

Rumors & Legends
Kyristan's personal sigil resembled the symbol of the Doomguard, suggesting he might've been a member of the faction at one point.