Walter was an officer with the Scarlet Moon Empire and the superior of Seneca and Andarc. Ten years prior to the Island Liberation War, he would meet Yohn, who had been brought into the world by Warlock's experiments and the two would grow close. Eventually, Walter would father a son with Yohn, Kyril. He was a colleague of Heinz in Scarlet Moon but Heinz would report his friend's actions and so Walter would be exiled from the Empire.
Eventually realising that Yohn appeared in the world at the same time that Rune Cannons began to be developed, Walter, with his companions, would begin an investigation into the devices. As they progressed in their investigation, he would begin to realise that Yohn too was from a different world and would work to find a way to get her home. On his investigations, he would often charge Seneca with Kyril's safety.
Following these clues would eventually lead him to the Island Nations and Middleport in particular before engaging in a battle against the pirate Steele. There, Walter would be hit by a blast from the Evil Eye, transforming him into a fishman. When the now-monstrous Walter made a move to attack Kyril, Andarc charged in and struck him down, ending his life.
Years later, after Kyril had defeated the Evil Eye inside the dome, he would be able to talk to his father through the power of Yohn. Walter and Yohn would then return to Yohn's world, together.
- Genso Suikoden Kiwami Encyclopedia, page 506