Here are several accounts of the description of the San Diego Comic-Con 2015 X-MEN: APOCALYPSE footage shown to the Hall H crowd.
And here's a description...
Via CB:
"Elements flash by as Jean Grey wakes up. She claims to have seen the end of the world. "I can feel all this death," she says but Professor X assures her it was just a dream. Apocalypse narrates, saying he's been called many things. Mystique and Quicksilver look upset. Magneto is cornered in a forest. Moira MacTaggert explains her tracking of Apocalypse. Characters flash by for their first appearances. Nightcrawler and Raven have a standoff. Magneto asks, 'Who the f--- are you,' after Apocalypse removes his hood. "Come and see," he says. Professor X says he can control all of us. Magneto forces him into Cerebro by pulling his chair with is powers. Cyclops can't control his powers. Chaos ensues. Professor X's eyes go black and he says, "I've never felt power like this before. The title card graces the screen, then the doors to Cerebro open and Charles is sitting in his chair, bald." [sic]