Skadaurak
Skadaurak, also known as the Red Terror of Mintarn, was a Red Dragon wyrm active around Mintarn circa the -2nd century DR. He was slain by the Red Dragon Hoondarrh, who desired to seize the wyrm's lair for his own.
Possessions
Skadaurak had amassed a vast collection of magic items before his death, but he largely saw these as a means to an end. He had planned to trade them in exchange for magical favors, specifically to wizards who might be able to grant him immortality.
His most prized item was Saldrinur's Slow Gem, a Halruaan item that allowed him to enter into long sleeps in which his body was kept in stasis, thus preventing aging.
History
In his lifetime, Skadaurak earned the title of the "Red Terror of Mintarn", and the island on which he laired would come to be known as Skadaurak Island in his honor.
In a quest for immortality, Skadaurak sought the aid of human spellcasters, but grew frustrated with their lack of power following the Fall of Netheril. Thus, he used Saldrinur's Slow Gem to enter into a stasis that would last hopefully until powerful magics—equivalent to those wielded by Netheril—had been rediscovered. His sleep lasted almost a millennium, and ended in the Year of the Singing Arrows, 884 DR, by which time few remembered his name and those who did largely thought he was a mere myth. Before he could prove them wrong, however, he was attacked by Hoondarrh almost immediately upon digging himself out of his lair. Still groggy from his sleep, he was no match for the ferocious younger dragon's spells and claws, and was quickly slain.
However, at some point either before or after his death, Skadaurak entered into the service of Asmodeus.
Centuries after Skadaurak's death, in the late 15th century DR, Asmodeus manipulated circumstances through the archdevil Zariel to have Shadaurak's spirit be summoned to Toril to allow the dead wyrm to pursue revenge against Hoondarrh. By playing on the desire for revenge held by the wizard Helene after a deadly encounter with Hoondarrh, Zariel prompted her to summon Shadaurak's spirit through a Moonwell on the island of Moray, which allowed the dragon to possess a dragonborn pirate named Rayonde. Through Rayonde, Shadaurak raised an army that conquered Moray and threatened the rest of the Moonshae Isles. When Rayonde's former companions finally slew him on Skadaurak Island, this allowed Skadaurak to leave the dragonborn's body and instead possess Hoondarrh. With his revenge complete, he turned his attention to helping Asmodeus claim control over Helene, whom the dark god had groomed to be his warlock.