SPOILERS: If you want to go in to reading this and other X-Men back issues fresh, stop reading!
House of X #5 takes us into the mechanics of Krakoa along with some key mutants who contribute to this mutant island nation. As we look into important back issues that relate to this issue, we’ll be focusing on Hope and her companions that make this new era of mutantdom possible.
Hope and the Five Lights
Hope is the central figure in the group of five mutants who enable the rebirth of mutants on Krakoa. Hope first appears as in X-Men #205 during the Messiah CompleX story as the first new mutant birth since the Decimation. She gets taken to future to be raised by Cable. The trilogy of her story continues in Messiah War and culminates in Second Coming.
Once fully established in the present, we see her role shift to locating five new mutants identified by Cerebra, dubbed the “Five Lights” in Uncanny X-Men #526 to #529 and Uncanny X-Men the Heroic Age #1. This leads into Hope’s own series, Generation Hope. Interestingly, there are also five mutants responsible for mutant rebirth on Krakoa that potentially mirrors the five lights.
Tempus and Goldballs
Both Tempus and Goldballs are more recently introduced mutants. They are from the “Class of Bendis” as they first appear during Brian Michael Bendis’s run on Uncanny X-Men (2013) 3rd series. Tempus first appears in All-New X-Men #1 and Goldballs first appears in Uncanny X-Men (2013) #1. Their stories are mostly contained in this series and occasionally crossover in issues of All New X-Men also penned by Bendis.
We’ve covered Proteus in previous recaps mostly under the guise of being the son of this series’ most important star, Moira MacTaggart. Much of what explains how he now stands next to the X-Men here might be found in the most recent Astonishing X-Men #1-12 by Charles Soule. As a bonus, you’ll also find out how Charles Xavier has returned to life (and is now walking), if that is indeed how Hickman decides to explain Xavier’s current status quo.
The final of the five mutants is Elixir. Elixir was first introduced in New Mutants (2nd series) #5. He was last featured in the Cullen Bunn-written Uncanny X-Men series.