Apocalypse (the Character, Not the Movie)
Apocalypse is the First Mutant. Under the name En Sabah Nur, he became known as a god throughout the history of ancient Egypt, able to perform feats such as create the pyramids. In the film, he has the ability to transfer his body and amass powers from other mutants, and it’s here where the film begins. During his transfer process, some of his subjects turn on him, destroying the pyramid and killing his Four Horseman. One of them is able to live long enough to create a shield that protects him for the next thousands of years.
The film implies that our titular villain is responsible for our various faiths and religions without really going into why or how that even works. Sure, the Four Horseman is valid, but how does that go for say, the Nazi belief system? Why did the Egyptians think that he was a “false god”? Why does he think that Charles and the human race are false gods? These are things that the film doesn’t answer, nor is it all that clear if he’s fully aware of the Phoenix power inside Jean Grey or just realizes that she is stronger than him.