|Date of Birth:||Unknown|
|Date of Death:||Lucius 2: The Prophecy|
|Cause of Death||Shot with salt laced bullets by Lucius|
Isaac Gilmore was another son of Lucifer and was considerably the half-brother of Lucius Wagner. Not too much is known about him, but in Lucius II: The Prophecy, he is the main antagonist and rival of Lucius.
Isaac was born at St. Benedict Memorial Hospital, many years before Lucius was. Upon reaching adulthood, he set out for the small town of Ludlow to fulfil the religious prophecy as described in the Book of Revelations.
After Isaac burns Ludlow's cornfields to sound the first trumpet and somehow summons a meteor to Earth to sound the second trumpet, Lucius makes his presence known by poisoning the town's water supply, which sounds the third trumpet and then proceeds to shut down the power plant, sounding the fourth trumpet.
Attempting to secure his standing, Isaac goes to the locust farm in an attempt to sound the fifth trumpet, he is confronted by Lucius, who already released the locusts and then throws a container of salt at Isaac, causing him to burst into flames, seemingly destroying him.
Later, Isaac is revealed to have been supernaturally resurrected and reappears on top of a building in Ludlow, before lunging down into the streets. Isaac tries to kill Lucius with his hellfire, but Lucius manages to shoot him several times by using a shotgun loaded with salt-laced bullets, successfully killing him.
- Because of how lethal salt was to him as a demon, it is likely that salt is also lethal towards Lucius.
- At the end of the game, Lucifer remarks that he has many sons meaning there are more demonic brothers "related" to Isaac and Lucius.
- It is possible that his name and his burning of cornfields is a reference to the Children of the Corn Series as the main antagonists are both named Isaac.
- Isaac's appearance also holds a similarity to Courteny Gains' portrayal of Malachai from the 1984 adaption of Children of the Corn. This is ironic because Isaac Chroner, the main antagonist of the Children of the Corn, bears some resemblance to Lucius.