11 "And so Azmartin led his men into the Witch of Emeron's lair. 12 There they fought the spirits of the dead which were in both corporeal and incorporeal forms. 13 They set upon Azmartin and his men. 14 Some where killed and came back to attack their fellows. 15 Azmartin and his men beseeched Virtoaa's aid. 16 Virtoaa's aid, and defeated them with His divine light of the sun. 17 Still, his men where shaken. What where these new creatures? They were not Demons of the Earth, nor Hob-Gobel.
18 "God sent an angel who appeared like a man clothed in lightning. 18 He told them: 'One of my fallen brothers, Orkus, has stolen one of the keys from Hell. He has escaped and commands the spirits of the deceased and can prohibit them from entering Hell. They are not longer dead, but undead.'
19 "Azmartin marveled at this revelation, and shuddered, for Demon Prince of Undead would forever plague mankind with the fear of the undead."
The Book of Origins 38:11-19, The Word of Virtoaa--The First Testament
That's right, I spell Orkus with a "k!"
Orkus is called the "Prince of Undead" for a reason: he created and enabled the creation of undead in Domikka. The wand of his is one of the Keys to the Gates of Hell. With it, he can determine which souls get in and others who are doomed forever in the Shadow Realm to serve him.
Otherwise, he very much like the Orcus you'd read about for years: fat, bloated, goat-headed, and evil.
And here's Tim Brannan's version of Orcus.