X-Men: Apocalypse introduces a new version of Angel, who becomes one of Apocalypse’s allies. Fans might remember though that a different Warren Worthington previously appeared in X-Men: The Last Stand (two separate versions exist thanks to the Days of Future Past reboot of the timeline).
When we first see Angel, he’s in a cage fight with another mutant we’ve seen before – the Blob, who turned up in X-Men Origins: Wolverine as played by Kevin Durand. Later, Apocalypse gives Angel metal wings, as well as an odd blue face tattoo. This is a reference to how En Sabah Nur’s power boost gives him blue skin in the comics.
Finally, one last easter egg revolving around the character is the song that Angel is listening to when Apocalypse recruits him into his gang is the perfectly-chosen “The Four Horsemen of the Apocalypse” by Metallica.