Complex sentence: A belligerent Foxy serves as his gunner and is not accepted as a team player by others until during a bombing mission against the Japanese, he makes the ultimate sacrifice in trying to protect the other crew members when the bomber is shot down behind enemy lines.
Split into simpler sentences: A belligerent Foxy serves as his gunner and is not accepted as a team player by the others. During a bombing mission against the Japanese, however, he makes the ultimate sacrifice in trying to protect the other crew members when the bomber is shot down behind enemy lines.