In the episode Razor's Edge, Keith and Krolia experience visions of each other's pasts. In Keith's visions, he sees how she met him after crashing on Earth after preventing the Galra Empire from learning about the Blue Lion's location on Earth. Keith's father discovered her ship and presumably nursed her back to health. During their time together, they fell in love and she shared details of her mission with him and showed him the Blue Lion. Some time after this, they conceived a child. Krolia wanted to name their son Yurak, but he suggested Keith instead. Eventually, more Galra scouts arrived, picking up on the Blue Lion's signature.
He helped Krolia stop them by planting explosives on their ships, but he was injured in the attempt. Worried for his and Keith's safety, Krolia decided to return to the Galra and lie about the Blue Lion's location, as it was the only way she could keep them safe. Before leaving, she kissed Keith goodbye and left her knife with his father. In Krolia's vision, she sees a young Keith standing in front of a gravestone in tears and realizes that her lover had died at some point. His cause of death was revealed by his son in a flashback to have been due to going back into a burning building, where he was killed in action.
- The name "Yurak" that Krolia wanted to name Keith is a reference to Yurak of Defender of the Universe.
- The showrunners have stated Keith's father was a firefighter, and the black vest that Shiro wore in the first two seasons once belonged to him.