Like their Earth-616 counterparts, all four members of this incarnation of Power Pack are children of James Power and Margaret Craig. They received their powers in a similar manner as their Earth-616 counterparts (namely from a dying Aelfyre Whitemane in order to save their parents and stop the Snarks from destroying Earth), though all of them were 2 - 3 years older than their Earth-616 counterparts upon receiving these powers. After successfully stopping the Zn'rx, they continued to work together as a superhero team while always making sure to keep their superhero adventures secret from their parents.
Over the course of their adventures, the team moved to New York and teamed up with other heroes like the Avengers, X-Men and the Fantastic Four. They also recruited Franklin Richards as an honorary fifth member, even though he had no superpowers of his own at the time. During their adventure in Asgard, Power Pack briefly changed their team name to "Warriors Four" to blend in after an Asgardian girl they saved from a group of Dwarves called them such. 
This incarnation of Power Pack are the titular stars of 11 miniseries, each consisting of 4 issues.
The first, simply named Power Pack, debuted in 2005 under the Marvel Age (now Marvel Adventures) imprint. Written by Marc Sumerak and penciled by Gurihiru, it mostly ignored previous Power Pack continuity and its versions of the title characters, and appeared to be geared toward young children. Although the four-issue series was not released under the Marvel Age or Marvel Adventures imprint because of editorial decisions, the later series have since been released under the Marvel Adventure imprint and revealed to exist in the Marvel Adventures universe.
A second Power Pack mini-series by the same creative team, X-Men and Power Pack debuted in October 2005. The series guest-starred various members and villains from the X-Men comics, including Cyclops, Wolverine, Sabretooth, Beast, Mystique, and Nightcrawler.
A third Power Pack mini-series, entitled Avengers and Power Pack Assemble! debuted in April 2006. This series teamed the Pack with various members of the Avengers (Captain America, Tony Stark, Spider-Man and Spider-Woman). Issues #3 & #4 were a two-part adventure in which the Pack and the Avengers battled Kang the Conqueror
A fourth Power Pack mini-series, entitled Spider-Man and Power Pack, debuted in November 2006. The series featured Spider-Man and some of his rogue's gallery, such as the Vulture, Sandman and Venom. The miniseries included two sub-plots: in one, Spider-Man was reduced in age and temporarily joined the Power siblings; the second involved the Venom Symbiote costume.
A fifth Power Pack mini-series, Hulk and Power Pack debuted in March 2007, following the events from the Spider-Man and Power Pack mini-series. The series involved the Hulk and his enemies the Absorbing Man, Abomination and Zzzax. The mini-series was drawn by David Williams (except for issue #3, which was drawn by Andy Kuhn).
A sixth Power Pack mini-series, Fantastic Four and Power Pack, debuted in July 2007, co-starring the Fantastic Four, who made a previous appearance in issue #3 of the first Power Pack mini-series. Gurihiru returned for the artwork; however, Fred Van Lente replaced Mark Sumerak as writer. The series pitted the Pack against the Fantastic Four's enemies and also featured Franklin Richards (Earth-5631), who was a member of Power Pack as Tattletale in the original series in the Earth-616 Marvel Universe.
A seventh Power Pack mini-series, Iron Man and Power Pack, debuted in November 2007, co-starring Iron Man, who previously appeared in the Avengers & Power Pack: Assemble mini-series. The series was written by Marc Sumerak and the artwork was done by Marcelo Dichiara.
A eighth Power Pack mini-series, entitled Power Pack: Day One debuted in March 2008. The series, which featured the same creative team as Fantastic Four & Power Pack (Fred Van Lente and Gurihiru), focuses on the origins of the team and the incorporation of their honorary member, Franklin Richards. There are also back-up stories about each of the Power siblings with artwork by Colleen Coover.
A ninth series, Skrulls Vs. Power Pack, made its debut in July 2008. The storyline involved the Power Pack encountering the alien Skrulls. This miniseries also introduced the Kymellian Kofi Whitemane to this continuity. The creative team was Fred Van Lente as writer and Cory Hamscher as artist. Gurihiru provided the covers and the colors.
A tenth miniseries, Wolverine and Power Pack, made its debut in November 2008. Wolverine had previously appeared in the X-Men and Power Pack miniseries. The series reunited the original creative team of Marc Sumerak and Gurihiru and also included Scott Koblish. Logan and the four children confronted Sauron, faced the Danger Room, and defended the Xavier school against Sentinels, giant robots programmed for anti-mutant genocide. Logan and Power Pack also had adventures together in 19th-century New York City and present day Tokyo.
An eleventh Power Pack miniseries began April 2010, with Thor appearing and co-headlining, called Thor and the Warriors Four. The creative team was writer Alex Zalben and artwork once again by Gurihiru. Thor and the Power children confront an evil plot of Loki in order to save the Powers' grandmother. The series also contains a back-up adventure of Hercules telling the story of his Twelve Labors while babysitting the Pack.
- After moving to New York City the children attended 'Public School 616', a direct reference to the mainstream Marvel reality, Earth-616
- 5 Power Pack (Earth-5631) Members
- 45 Appearances of Power Pack (Earth-5631)
- 5 Minor Appearances of Power Pack (Earth-5631)
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- Team Gallery: Power Pack (Earth-5631)