- Script
- Len Wein (credited) (plot pp. 1-6, 9, 13-22); Chris Claremont (credited) (plot and script)
- Pencils
- Dave Cockrum (credited)
- Inks
- Bob McLeod (sourced) (pp. 1-6, 9, 13-22); Sam Grainger (pp. 7-8, 10-12)
- Colors
- Glynis Oliver (credited)
- Letters
- Tom Orzechowski (credited)
- Editing
- Len Wein (sourced) (original material editor)
- First Line of Dialogue or Text
- I called you here, X-Men, because there's something I want to tell you all...
- Genre
- superhero
- Characters
- Ani-Men: Ape Man [Gordon Keefer] (origin) (villain); Bird Man [Henry Hawk] (origin) (villain); Cat Man [Townshend Horgan] (origin) (villain); Dragonfly [Veronica Dultry] (villain) (introduction, origin); Frog Man [Francois Le Blanc] (origin) (villain)
The Avengers: Beast [Hank McCoy]
X-Men: Angel [Warren Worthington III]; Banshee [Sean Cassidy] (featured); Colossus [Piotr Rasputin] (featured); Cyclops [Scott Summers] (featured); Lorna Dane; Havok [Alex Summers]; Iceman [Bobby Drake]; Marvel Girl [Jean Grey]; Nightcrawler [Kurt Wagner] (featured); Professor X [Charles Xavier] (featured); Storm [Ororo Munroe] (featured); Thunderbird [John Proudstar] (featured); Wolverine [Logan] (featured)
Count Nefaria [Luchino Nefaria] (villain); Eel [Leopold Stryke] (cameo, flashback); Lieutenant General Fredricks; Moira MacTaggert; Plantman [Samuel Smithers] (cameo, flashback); Porcupine [Alexander Gentry] (cameo, flashback); Reverend Craig; Scarecrow [Ebenezer Laughton] (cameo, flashback); Rahne Sinclair; Unicorn [Milos Masaryk] (cameo, flashback)
- Universe
- Marvel : mainstream
- Synopsis
- The old X-Men quit, but Cyclops stays behind to lead the new team. Nefaria takes over Valhalla air force base, and the X-Men move in to stop him.
- Reprints
- from The X-Men (Marvel, 1963 series) #94 (August 1975) [recolored, minus page 9 with five new pages added (pages 7-8 and 10-12).]
- in El Asombroso Hombre Araña Presenta (Novedades, 1988 series) #35 (Diciembre 15 de 1988)
- in Superaventuras Marvel (Editora Abril, 1982 series) #98 [Do original, da história, foram usadas as páginas: 13 a 22.], #98 [Do original, da história, foram usadas as páginas: 1 a 12.]
- in L'Uomo Ragno (Edizioni Star Comics, 1987 series) #55 (30 Agosto 1990)
- in X-Men Classic: The Complete Collection (Marvel, 2018 series) #1 (2018) [pages 7-8 and 10-12]
Chapter One is entitled "The Doomsmith Scenario!"; Chapter Two is entitled "Death O'er Valhalla High!"