Gideon is the father of Alex and Kayla, and had an abusive relationship with his wife Ash (not Ash Thorane). He died during a battle between the rebels and the Authorities.

[Alex's] father and mother had both been with the rebels, and even commanded a few attacks. [Alex] could imagine his father charging into battle, fighting fiercely against the Authorities’ forces.

– Fallen Nation

"His father left his mother. They… didn’t have a good relationship. He beat her and then abandoned her when she was pregnant. I don’t know all that happened, but that’s what she told me when I was tending to her in the hospital wing. His father was very violent. He had regular fits of rage. I heard he even killed one of the rebels he commanded. He was uncontrollable and shouted all the time. Actually, I heard that the heads of the resistance movement sent him out at the front of the battle in hopes that he might not return. They got their wish. He was killed in the fighting, and I heard someone say that he went insane on the battlefield right before he died. Started screaming and beating his fists on the ground. His fellow rebels were so terrified they didn’t even try to help him when soldiers surrounded him."

– Mel to Ash in Fallen Nation