General Hayden

General Hayden is the human military commandant of the UAC space marine garrison in the Doom 3 novels.

Behind the scenes
In the 2016 reboot, Hayden has been reinterpreted as a scientist who came down with cancer and converted himself into cyborg going by the name Samuel Hayden, who is the chairman of the UAC and highest command on Mars.

Some particular differences include the fact taht General Hayden is human in the novels in 2145. Whereas Samuel Hayden was a cyborg by 6 months after Argent Tower was completed circa 2127. The only way for them to co-exist is if General Hayden was a decendent of Samuel Hayden.