X-Factor #5 (1986 Series)

1st appearance of Apocalypse (shadowed cameo).

It's a classic super-hero/super-villain throw-down when X-Factor must battle the Alliance of Evil (Frenzy, Tower, Stinger, and Timeshadow) for the life of a mutant. Featuring a new menace by the name of Apocalypse, an evil mutant who will become a major thorn in the sides of the X-Men and X-Factor.