Superheroes seem to get stronger all the time in comic books. And sometimes they have kids who are even stronger than they are. As longtime superhero characters marry and have kids, they create in some ways a new generation that will grow up to replace them. This never really happens, but often, the kids are even more powerful than their parents.
Some examples are obvious, like Franklin Richards, while others may not be. Whether it's DC Comics, Marvel, Image, or other superhero stories, nearly every major character in the genre has a child that rivals them in power.
10 Hope Summers
Hope Summers is the adopted daughter of Cable, a powerful child of superheroes himself. Hope was of such power that she became the target of many. She was the first mutant born in the aftermath of the cataclysmic House of M, and others from the future feared her potential role in an apocalypse. So far, Hope has used her powers to create. As part of the Five, she plays an instrumental role in resurrecting mutants. This is a result of her extraordinary ability to mimic other superpowers as well as manipulate them, which puts her far beyond Cable in terms of power.
9 Cable
Cable is one of the most powerful mutants alive. The son of Cyclops and Madelyne Pryor, the clone of Jean Grey, he possesses extraordinary telekinetic and telepathic abilities. His powers are so great that he once used them to withhold the techno-organic virus within his body from spreading. Cable is also an expert marksman and martial artist, which he displayed time and time again as the leader of X-Force and also recently in the X Of Swords event.
8 Damian Wayne
Like his father, Damian Wayne has no superpowers, but he has all of his Batman's attributes at a frighteningly young age. The most recent Robin is a highly trained martial artist thanks to his mother Talia al Ghul, and the League of Shadows. He's a forensic scientist, an engineer, and also a cunning businessman. He's only ten years old. Damian Wayne seems poised to outstrip his father in every way, especially in ways that Batman may eventually regret and probably does already.
7 Invincible
Mark Grayson is the son of Nolan Grayson, who is also the superhero Omni-Man. Mark grows up to be Invincible, and possesses all of his father's powers: super-strength, speed, invulnerability, flight, decelerated aging, enhanced healing factor, and more. He is generally more adept in each of them than Omni-Man.
Invincible is full of shocking moments. One of them happens early on when Mark learns he's actually a descendant of aliens. Omni-Man is a member of a race of peaceful aliens called the Viltrumites, who came to Earth to help mankind.
6 Legion
Legion is the son of Professor X, Charles Xavier, and perhaps one of the most powerful mutants alive. His ability to alter reality makes him an Omega-Level mutant and extremely dangerous. The extent of his powers was on full display when he went back in time to kill Magneto and accidentally killed his father, ushering in the Age of Apocalypse. The massive 90s event had aged well in some ways, including showing that David Heller could survive even beyond his own death and destruction.
5 Scarlet Witch
The Scarlet Witch is in some regards the most powerful being in Marvel Comics. She wiped out nearly all of mutantkind with a single phrase in the House of M event. The repercussions of her actions reverberate through the comics to this day. Some debate exists over whether or not Wanda Maximoff is the daughter of Magneto or even a mutant herself, but her ability to alter reality, manipulate time and space, to say nothing of her prowess as a sorceress, makes her incredibly formidable.
4 Rachel Summers
Rachel Summers is potentially the most powerful Summers child in the Marvel Universe. She certainly was at one point. Rachel is the daughter of Cyclops and Jean Grey from the Days of Futures Past alternate timeline. She is an extremely powerful mutant with telepathy, telekinesis, empathy, and temporal astral projection all in her arsenal. She also for a long time possessed the Phoenix Force, and once defeated Galactus as a member of the Excalibur, proving her a true cosmic force.
3 Jack-Jack
The Incredibles are in many ways based on the Fantastic Four, and they continue that tradition by having a young child with extraordinary gifts. Jack-Jack is the baby in the family but he has a variety of superpowers and can use them interchangeably.
Jack-Jack can run fast, flame on, turn invisible, and fire laser beams from his eyes. And that's only a few of his many abilities, which seem to run the gamut of most known superpowers.
2 Superboy
Superman is the proud father of Jon Kent, the newest version of Superboy. Like Damien Wayne, his friend and occasional partner, Jon Kent has the potential to surpass his father. He already has all of Superman's main powers, including superhuman strength, hearing, speed, and vision, heat vision, X-ray vision, freezing breath, and flight. But according to Batman, thanks to Jon's combined human and Kryptonian DNA, he is likely to become more powerful than Kal-El.
1 Franklin Richards
A lot of the most powerful characters in Marvel Comics can alter reality. Franklin Richards can create realities. The son of Reed and Sue Richards was long thought a mutant, but recently that was cast into doubt, a retcon sure to join some of the worst Marvel retcons. But Franklin remains a powerhouse, going back to when he was just a child. He displayed the ability to create a pocket universe during the 90s Heroes Reborn event. Among his known powers are matter and energy manipulation, energy projection, telekinesis, telepathy, astral projection, and precognition, teleportation, and immortality.