Jonathan Hickman is currently blowing minds and reshaping the X-Men with House of X and Powers of X, and fans are eagerly anticipating his plans for the team after the dual series event is finished shaking things up. We have seen a preview of his new X-Men series, which looks to focus heavily on the Summers and Grey related characters like Cyclops and Jean Grey.
As X-fans have learned over the years, the Summers-Grey bloodline is highly-coveted by Mr. Sinister due to its potential to produce powerful mutants. Scott Summers and Jean Grey may not have any natural children in the mainstream Marvel reality/timeline, but there have been a number of powerful descendants from alternate timelines and realities that we will be examining today.
10 TYLER DAYSPRING
Tyler Dayspring has a very confusing lineage, which is to be expected for the son of Cable, the time-traveling mutant warrior from the future. Cable's wife in the future was named Aliya "Jenskot" Dayspring, and she had a son named Tyler. While his real father was never revealed, it was rumored that Tyler was the son of Cable's clone Stryfe, who had raped Aliya while she was his prisoner.
Tyler would also travel back to the present, eventually becoming the villain known as Genesis. He possessed limited telepathic abilities that allowed him to view other people's memories and project them as solid holograms. As Genesis, he wore advanced body armor based on the designs of Apocalypse, though his armor and abilities failed to save him from a Wolverine's berserker rage.
9 MEG FROST
Chris Claremont returned to the X-Men to tell an interesting alternate reality tale set in a world where the X-Men aged in real-time since their creation in the 60s, meaning the modern stories would then feature their children and grandchildren. GeNext and the sequel GeNext United introduced a few interesting legacy characters of the X-Men, including Meg Frost/Mind Witch.
Megan Frost-Summers is the oldest child of Scott Summers and Emma Frost in this reality and possesses enhanced telepathic abilities as well as limited telekinesis that allows her to levitate. Meg's upper power levels haven't really been reached as she was still a young mutant-in-training, but the mini-series revealed she had mastery over many psionic abilities like her mother.
8 RUBY SUMMERS
Another possible daughter of Scott Summers and Emma Frost named Ruby Summers first appeared in Peter David's X-Factor run and was revealed to be an instrumental part of what was known as the Summers Rebellion, a futuristic event that had been teased in the present by time-travelers for years.
Ruby gained variations of both of her parents' powers, as she is able to shoot black-tinged optic blasts. She is also able to transform her body into a ruby quartz form, which grants her near-invulnerability and immortality, though it's possible if she reverts to her organic form she would age many years instantaneously.
Nathan Summers is the son of Cyclops and a clone of Jean Grey named Madelyne Pryor, who was created by Mr. Sinister after the "death" of Grey to create a weapon against Apocalypse. young Nathan was that weapon, but Apocalypse soon infected the young baby with the techno-organic virus, forcing the infant to be taken to the future in order to survive.
Nathan would grow up in the future but return to the present as the man known as Cable, still infected with Apocalypse's T/O virus. Nathan was able to keep the virus at bay due to the incredible levels of telekinetic and telepathic power at his disposal, though the constant need to fight the T/O virus reduces his active power levels greatly.
6 RACHEL GREY
Rachel Grey (originally known as Summers) is the biological daughter of Scott Summers and Jean Grey, however, she comes from a future timeline known as the "Days of Future Past." She was sent back to the present in order to prevent her apocalyptic timeline from existing, which results in her being exiled to the past.
Like her mother and half-brother Cable, Rachel is an incredibly powerful telepath and telekinetic, though she lacks the training the rest of her family has received. However, Rachel also has a connection to the Phoenix Force like many members of her family, which drives her potential power levels up, despite her lack of training.
5 HOPE SUMMERS
Hope may not technically be related to the Summers or the Greys by blood, she is still a powerful member of the family. She was the first mutant baby born since Scarlet Witch uttered "No More Mutants" during the House of M event. Hope's life and the future of mutantkind was in danger, so Hope was sent into the future to survive, where she would be raised by Cable.
Hope became Cable's adopted daughter, and the two spent years fighting for survival in the future before returning to the present. There Hope's powers manifested, and it was revealed she was able to mimic and enhance other mutant's abilities. She is also connected to the Phoenix Force, which allows her to draw from the energy of the cosmic force.
4 SCOTTY SUMMERS/RAVEN LEBEAU
When the consciousness of Alex Summers was transported into an alternate reality version in the Mutant X series, Alex woke up to discover he had a son named Scotty, with that reality's Madelyne Pryor. Scotty was a mutant with incredible psionic powers that allow him to draw on the energy of the astral plane to manipulate both matter and energy.
Havok's Cerebro unit also identified Gambit's adopted daughter Raven LeBeau as an Omega-Level mutant with the potential to be the most powerful mutant on the planet, though her powers were never shown. However, it was revealed that Raven was actually created by Sinister using the DNA of Alex Summers and Jean Grey, proving the potential power of the Summers-Grey genes.
3 DAVID RICHARDS
David Richards hailed from a variation of the "Days of Future Past" storyline, though he was first introduced in the pages of the reality-hopping Exiles. He was the son of Rachel Summers and Franklin Richards, who is an Omega-Level mutant and child of Reed and Sue Richards of the Fantastic Four.
David was a powerful psionic who was also able to manipulate reality, and he was described as being more powerful than Magneto, Professor Xavier, and the Phoenix Force combined. His power levels never reached the extreme levels he was prophesized to reach, and his actual comic feats make him the less powerful of the Hyperstorms.
2 NATE GREY
Nate Grey, also known as X-Man, has a similar origin to Nathan Summers/Cable, though his creation begins in another reality known as the Age of Apocalypse. In this alternate reality, Mr. Sinister was able to genetically combine the Summers and Grey bloodline to create Nate, who he grew to near adulthood in a lab before Nate escaped.
While the AoA was erased (temporarily), Nate Grey was able to escape to the mainstream universe. His psionic abilities were unhindered by the T/O virus like his "brother" Cable and Nate's pure genetic stock (Cable's mother was a clone) allowed for nearly-infinite levels of power, as seen recently in the Age of X-Man storyline, where Nate was able to create an entirely new reality.
Jonathan Reed Richard is also the son of Rachel Summers and Franklin Richards, from another variation of the "Days of Future Past" storyline. Jonathan's incredible psionic powers allowed him to become one with Hyperspace and control the fundamental forces of reality, making him an incredibly powerful threat that required the intervention of Galactus to defeat.
Both overpowered children prove that while the Summers and Grey genes are incredibly powerful, that can become a very dangerous combination when combined with Franklin Richards already phenomenal power levels. Of course, growing up in the "Days of Future Past" reality can't help much either.