Complex sentence: Due to the shock of being resurrected Galavan's memories are scrambled, causing Dr. Strange to mislead Galavan, making him beleave he is Azrael, and subsequently exclaiming himself to be the leader of the order of saint Dumont.
Split into simpler sentences: Due to the shock of being resurrected Galavan's memories are scrambled, causing Dr. Strange to mislead Galavan. Making Galavan beleave he is Azrael, Dr. Strange subsequently exclaims himself to be the leader of the order of saint Dumont.