Although due to its cancelation after season one, the show did introduce fans to a litany of very interesting characters. Most of the main characters in the show have incredibly enhanced abilities, but they are powers that fans of DC have seen before.
The origin of the heroes in Jupiter's Legacy is a very different story than most of the top characters in DC, but character traits can be traced back to the lore of DC. Not just powers, but similar ideals and skills can make these characters feel the same.
The Utopian / Sheldon Sampson - Superman / Clark Kent
When people think about The Utopian, there are many different ways he can be portrayed in their minds. Some see him as the strongest superhero Earth has. Some as the unquestioned leader of the Union of Justice. There are even several that see him as a symbol of justice based on his strong moral code. All of these traits of Sheldon Sampson line up with only one DC character, and that's the Man of Steel himself, Superman, a character depicted in movies several times.
Just as the symbol on The Utopian's chest speaks to justice, the shield on Superman's stands for the same ideals. Superman is seen by many as the face of the Justice League, and his standing within the group is rivaled by no one. Even in of power set, Utopian and Superman are similar between their strength, speed, and heat vision.
Paragon / Brandon Sampson - Superboy/ Jon Kent
Brandon Sampson has one of the most difficult tasks of any hero within Jupiter's Legacy lore, and that is to live up to his father. That is especially difficult when the father is the most powerful and respected hero on the planet. Brandon has a strong iration for Sheldon, but he always feels like he is in his shadow. That is a feeling Superboy knows all too well.
When Jon Kent was born, the pressure was on him right away to live up to being the first son of Superman. His powers came in at a young age, but just like Paragon, they were slightly unstable, and Jon didn't fully understand how to harness them from the get-go. Both sons of Earth's greatest hero, both struggling to live up to that moniker.
Brainwave / Walter Sampson - Martian Manhunter / J'onn J'onzz
Walter Sampson's importance to the history of the Union of Justice can't be understated, as he is the brother of The Utopian. While he may not be as strong as his brother, The Utopian relies on him as an important voice when it comes to making difficult decisions about what's best for the planet. Though they have several similar powers, Brainwave's biggest strength is his telepathy, which allows him to control people's minds, or outright rip people's minds from their bodies.
The most powerful hero in DC that utilizes telepathy is without a doubt J'onn J'onzz, The Martian Manhunter. While J'onn doesn't have the more drastic tendencies as Brainwave, he does have that same desire to make Earth a better planet, even it isn't his homeworld.
Lady Liberty / Grace Sampson - Wonder Woman / Diana Prince
When Grace Sampson went to the island with the rest of the team, she too gained immeasurable powers. She has many of the same skills as The Utopian, but she serves as a different symbol for the planet than he. Of the original six of the Union of Justice, Grace Sampson was the only woman on the team. As such, she became a symbol for all future female superheroes that aspired to the Union.
As one of the founding of the Justice League, Wonder Woman serves as that same symbol to women across the planet that aspire to be just like her. Just like Lady Liberty, Wonder Woman possesses many strong powers in the comics, matching the strength of her constituents within the Justice League.
Chloe Sampson - Supergirl / Kara Danvers
Just like her brother Brandon, Chloe grew up in the shadow of her parents, but while he chose to follow in their footsteps and become a superhero, Chloe chose to leave that all behind and pursue a different direction. Chloe possesses the powers to be amongst the best of the heroes, but she rebels against what her family stands for, even leading to several questionable choices.
Supergirl is known as the cousin of Superman, but she is her own hero, and at times living in Superman's shadow was too much for her. Kara went through a time when she wanted to be anything but Superman's cousin and be able to live her own life. Eventually, she goes on to become the hero she was born to be, but it was a journey for her to get to that point.
Skyfox / George Hutchence - Batman / Bruce Wayne
George comes from a bit of a troubled past, but some would say he has rebounded quite nicely in adulthood. Between inheriting millions from his father, and having a reputation as a playboy, life seemed to only get better for George after forming The Union. Outside of his money, what separates him from his former teammates is his genius intellect, which he uses to build different gadgets for combat, something a certain Dark Knight also does.
While Batman may not be superhuman like Skyfox, the intellect is certainly there, as he also uses the immense array of gadgets at his disposal to thwart crime. The billionaire playboy Bruce Wayne also serves as the financial backer of the Justice League, just as Skyfox does for the Union of Justice.
Blue Bolt / Richard Conrad - Doctor Fate / Kent Nelson
All of the Union of Justice were given powerful skills on that trip to the island, but Richard Conrad was given a little something extra. Part of Blue Bolt's power set is his power rod, and he can use this artifact to teleport himself or anyone holding it to any location of his choosing. Not much is known about the power rod, only that it chose Richard as the one to control it.
DC has an array of mystical items that its characters use throughout the years, but none may be more powerful than the helmet of Nabu. That helmet attached itself to Kent Nelson, making him the next Doctor Fate. The Helmet of Fate possesses many powers, but teleportation, even between dimensions, is one of Fate's more powerful abilities, just as those of Blue Bolt.
The Flare / Fitz - Green Lantern / Hal Jordan
Fitz has a complicated relationship with the rest of the Union of Justice, as he doesn't always agree with their philosophies on what's best for the planet. So much so that he stepped away from the team for quite a while. When he is working with them, he creates energy blasts that can be utilized as weapons.
Similarly, Hal Jordan is a member of the Justice League who is always most likely to go rogue and try and find a different outcome from what the rest of the team decided. Hal also spends time away from the team, as the Green Lantern is always off-world serving in the Green Lantern Corps. As a member of the Corps, his ring can generate energy constructs, somewhat similar to Fitz.
Blackstar - Darkseid
From what audiences have seen of Blackstar, he is the toughest opponent the Union of Justice has had to deal with. Blackstar has conquered planets and wiped out entire alien species, so he assumed he would be able to do the same to Earth. While the Union did defeat him, it was no small feat, as his super strength can match that of The Utopian, and his antimatter heart can blast right through people, instantly killing them.
Darkseid has a similar backstory, as one of the evilest DC Comics villains, coming to Earth seeking to conquer, only for Superman and the Justice League to take him down. Darkseid is the strongest threat the League ever faced, with the strength to the levels of Superman, and his Omega Beams that shoot from his eyes, incinerating whatever is in their path.