Stryfe comes back. The way that they handle him very much assumes a level of knowledge of the character's history. The problem is that they've barely used Stryfe since the 90s, during Nicienza's X-Cutioner's Song crossover. He had a fairly major role in the later-90s Adventures of Cyclops and Phoenix, when Scott and Jean had their honeymoon 3000 years in the future where they wound up raising Cable and it's a really long story let's just say that Stryfe has major daddy issues with Apocalypse and it shows in Messiah Complex. They do have a two-panel blurb, they don't go completely without it, but even with a pretty thorough grounding in X-continuity I found myself stretching to remember some of the references they've made in the 3 issues of this crossover thusfar. I can't imagine a newcomer finding it easy to follow.