Metaphysical / Paranormal event
Sometime around the Year 450, Saidro Vasvadan emerged from the Shadowfell in the northern islands (which now carry his name), establishing a base of operations in the Material Plane there and constructing his dread castle, Gor'fathal. It is believed that some number of acolytes or allies he had gathered within the Shadowfell travelled with him and spread themselves across the realms, gathering a small but fervent cult devoted to Vasvadan and his dark magics; historical records recount that Vasvadan built a sort of religion around himself, teaching his followers that he and his people were chosen to raise an army and usher Raen'dor into a new age. His power over death tempted some and terrified others, but both proved effective. By the year 455, Vasvadan was known among his followers as the Undying King-- and was prepared to introduce that name to the realms.