Zloy Volk
Zloy Volk was a "Scientist General" of the Vremya Union (COMIC: Slaver's Song [+]Loading...["Slaver's Song (comic story)"]) who was destined to create free mass time travel for all. He was erased from time by a young Jack Harkness on the orders of the Time Agency.
Volk's assassination caused doubt in Harkness, and would be the cause of his falling out with the Agency when he determined that they had ordered Volk's erasure to maintain their monopoly on time.
In the time locked computers of the Time Agency, a recording from the version of history where Volk existed showed him being honoured by a Balhoonian as the "Father of Time". (COMIC: Secret Agent Man [+]Loading...["Secret Agent Man (comic story)"])
To entrap Harkness, Addison Delamar bought information about Volk from the Time Agency and used it to create fake evidence that Volk had survived. Jack was lured into leaving the Doctor in order to track down a Sin-Eater resembling Volk. (COMIC: The Bidding War [+]Loading...["The Bidding War (comic story)"])