Demonic Voice

"'You should not let his location be discovered, you have failed us' - the Demonic Voice voices his anger for Olivia Pierce's incompetency to keep the location of the Doom Marine a secret"

The Demonic Voice is an unseen demon lord that appears during the Doom Slayer's quest to release the souls of the Wraiths.

Nothing is known about the Demonic Voice but it is indicated that it has a very high rank in hell as it can command lesser demons to hinder the Doom Slayer in his quest. Olivia Pierce was also shown to interact with the Demonic Voice when it expressed disappointment that she was unable to stop Samuel Hayden from discovering the tomb of the Doom Slayer.