The Witness
The Witness is a Daemon Prince of Chaos, unusual in that he is pledged to both Khorne and Nurgle.[1c]
History
Originally a Space Marine named Phrynon, he was Chapter Master of the Virdian Consulss. During the Abyssal Crusade his Chapter was sent into the Eye of Terror and was destroyed or corrupted by Chaos and becoming known as The Broken. Phrynon himself was corrupted, eventually being granted the gift of apotheosis by both Nurgle and Khorne and dubbing himself The Witness.[1a]
The Witness eventually made his home at Space Hulk and made his way towards the Ultramar System in 812.M41, intent on luring Marneus Calgar into a trap.[1a] Calgar led a boarding operation to destroy the Hulk, where the Ultramarines were beset upon by The Broken and their Daemonic allies. In the final battle, Calgar was able to banish The Witness back to the Warp after smashing in its skull with his Power Fists.[1db]