On August 1, 1942, Sion was named commanding officer of the 15th Infantry Division. With it he moved to the front, near Stalingrad, being subordinated to the Romanian 3rd Army, led by General Petre Dumitrescu. Sion was killed on November 24, 1942 at Bolshaya Doshchinka, during the Battle of Stalingrad, when his 15th Infantry Division was overrun and wiped out during the Soviet Operation Uranus. He was the only Romanian division commander killed in action during World War II.