Complex sentence: Everett's antihero would eventually battle Carl Burgos' android superhero, the Human Torch; however, as the U.S. entered the World War II, Namor would aid the Allies of World War II against Adolf Hitler and the Axis powers.
Split into simpler sentences: Everett's antihero would eventually battle Carl Burgos' android superhero, the Human Torch. When the U.S. entered the World War II, Namor would aid the Allies of World War II against Adolf Hitler and the Axis powers.