Talk:Demonic-Undead Physiology/@comment-4714517-20161217104142/@comment-4867780-20161217135628

That's how I understood it as well. Basically, Orcus had a phase during which he was an undead demon lord, and specifically took on the name "Tenebrous" during this period. So "Tenebrous" effectively fits the description, and the full resurrection that followed ended "Tenebrous" and brought back "Orcus" the demon lord, without his former deity status.