Complex sentence: Known objects in his collection are Excalibur, the Spear of Destiny, Alexander the Great's armor, a polar bear hunting trophy, and a taxidermy rhinoceros in his collection and the ability to tell the difference between a fake artifact and a real one.
Split into simpler sentences: Known objects in his collection are Excalibur, the Spear of Destiny, Alexander the Great's armor, a polar bear hunting trophy, and a taxidermy rhinoceros in his collection. Steranko has the ability to tell the difference between a fake artifact and a real one.