X-Men Days Of Future Past after credits scene explained

Spolier Alert!

   I you haven't seen the movie yet and don't want to have it spoiled, stop reading.

   At the end of what seemed like an endless scrolling of credits true to tradition there was an after credits scene which was worth the wait.

   We are taken to the Sahara desert and we see a robed, hooded figure on top of a hill with his arms raised up in the air almost as if he were praying, as the camera moves forward we see that he is in fact manipulating huge blocks of stone and creating the Pyramids all the while being worshipped by a huge crowed who constantly chant "En Sabah Nur." (I was geeking out at this point) The camera then pans over the hooded figure's shoulder to reveal a pale white man who is non other than Apocalypse! The very first mutant.

   We also see four figures on horse back, these are none other than the four horsemen, Apocalypse's most trusted minions, War, Famine, Pestilence and Death. Its a pretty short scene but filled with little details as to what's to come. After all the next movie in the franchise is literally called X-Men: Apocalypse.

   So why is this such a big deal? Well, he is one of the big baddies, incredibly powerful and routinely brainwashes other mutants into carrying out his will, even done to Wolverine! He rarely keeps the X-Men brainwashed though and his goal was to rule the world.