The Gruppenführer is the commander of the Aryan Socialist Union's Suicide Corps, the recovery team who was sent to retrieve The Twelve Knights Led by Brunhilda from the U-1324. He is the only man, other than Ratchman, to get emotionally worked up over the latter's bombastic pronouncement of his mission. Feller leads his men down to the U-1324 using a special diving pod to connect with the U-boat's hatch. Getting caught up in a firefight with Revy, he is the only member of his team to set foot in the U-1324 to make it out alive, recovering the painting in the process.

When Revy and Dutch assault the Aryan Socialist Union aboard their recovery ship, he attempts to arm himself with a MG42 to fight back, but is shot in the back by Revy in the ship's magazine. In the manga, he is last seen fighting Revy inside the submarine; his fate afterwards is unknown.