Lucan has served his empire's war effort for over 2000 years. This life has made him a proud and sadistic warrior, affiliated with the Viltrum Empire. His abilities include extraordinary strength, flight, and near invulnerability. Lucan is the first Viltrumite that the protagonist, Mark, encounters apart from his father, Nolan. His goals involve enforcing the dominance of the Viltrum Empire across the galaxy. Lucan is one of Viltrum's most dedicated soldiers, always ready to aid their galactic conquest. This involves planetary subjugation, with an expandive empire that already encapsulated thousands of planets. He holds his lineage in high regard and advocates for the execution of Viltrumite traitors.

Paul Cha, also known as Multi-Paul, is a supervillain with the ability to duplicate himself. He is also Dupli-Kate's twin brother. He is an elite assassin for the secret criminal organization, the Order. His superior, Mr. Liu, is the one he directly reports to.

Scott Duvall, better known as Powerplex is a supporting antagonist in Invincible, serving from Season 3 and onward. He is a delusional and emotionally unstable scientist, who irrationally desires revenge on Invincible for his unintended role in the deaths of his sister and niece as well as the self-inflicted deaths of his wife and son.

Peter Parker, also known by his superhero alias Spider-Man, is the main character (alongside Miles Morales) of the Marvel's Spider-Man series. He is the playable protagonist of Marvel's Spider-Man, a supporting character in Marvel's Spider-Man: Miles Morales, and the playable dual protagonist of Marvel's Spider-Man 2. A resident of New York City, Peter gained his superhuman spider-powers and abilities after a bite from a radioactive spider at age fifteen. Opting to maintain a secret identity, he employed his newfound abilities and crafted web gadgets to protect New York. Eight years deep into his superhero journey, Peter is a seasoned and adept crime fighter but frequently grapples with balancing his superhero duties and personal life. As the Spider-Man persona, Peter fought various criminals, sharing a longstanding rivalry with Wilson Fisk. He spent eight years collaborating with Yuriko Watanabe to bring Fisk down, but doing so unleashed deadlier organized crime. Peter was the sole Spider-Man until he was supported by Miles Morales, a friend who also gained spider powers. Outside the mask, Peter worked as a lab assistant for his mentor, Dr. Otto Octavius, and grew up under the nurturing care of his Aunt May Parker. Romantically, Peter has been linked with Daily Bugle reporter Mary Jane Watson, whom he met during middle school along with his best friend, Harry Osborn.

Battle Beast is a brutish Leonine warrior who seeks worthy opponents to fight across the universe. While savage and sadistic upon defeating his enemies, Battle Beast still shows an honor in his refusal to kill weak, unworthy foes. Previously, he viewed his empowering thirst for battle as a gift but soon realised it was a curse. Battle Beast believes the only way he can free himself of this curse is through the glorious death he so greatly desires.

Kregg is a major antagonist in Invincible, debuting in Season 2 and onwards. He is a high-ranking Viltrumite general and second-in-command of the Viltrum Empire, dedicated to aiding the Viltrumite mission to establish it as the only empire in the universe. Kregg was born on planet Viltrum and is thousands of years old. Early in his life, he would fall victim to The Scourge Virus and lose his eye. Sometime during his life, he would assume a high-ranking position in the Viltrum Empire and serve under the current Grand Regent, Thragg. Kregg remains the general of the Viltrum Empire and a crucial part of the army.

Angstrom Levy is the secondary antagonist of Invincible, serving from Season 2 and onward. He was a brilliant human with the ability to traverse throughout different dimensions. Seeing all the possible realities the multiverse held, he sought to pacifically innovate and save his reality by gaining the knowledge from his alternate selves. His noble plan would go awry when Invincible intervened, unwittingly disfiguring him and granting the fallen pacifist the memories of all his alternate selves. Driven insane, Levy became obsessed in his quest of vengeance against Invincible. During his reckoning, Levy attempted to assassinate Debbie and Oliver Grayson but was defeated by Invincible in a battle across the multiverse until he was himself killed by his arch-nemesis. However, he was saved by The Technicians, whom he teamed up with to exact revenge and bring forth a team of evil Invincibles to begin a devastating war on Earth.

He is a version of Mark Grayson that comes from a different multiverse. In his universe, he still becomes Invincible, only he chose the path of a supervillain. Stripevincible aided his evil alien father, Omni-Man, in conquering Earth. Now, Invincible is an ally of the Viltrum Empire, as shown in his different suit. This variant is a lot louder and prouder than the others, likely a result of being around the mighty Viltrumites.

Allen the Alien, or simply Allen, is a Unopan and a representative of the Coalition of Planets. He was born in breeding camps designed as a way to repopulate the Unopans after they were nearly wiped out by the Viltrumites, as well as a sort of countermeasure against them. While his role as a Viltrumite countermeasure did not succeed, he would go on to become an evaluation officer for the Coalition, visiting different planets across various galaxies in hopes of finding a warrior strong enough to stand against the Viltrumites. After a close brush with death, Allen gained increased strength and was able to compete with the elite Viltrumites in combat.

Cecil Stedman is a major character in Invincible. He is the director of the Global Defense Agency. Following the massacre of the Guardians of the Globe, he sought to identify the murderer but quickly realized it was actually Omni-Man. Since his departure from Earth, he began the creation of numerous advanced superhuman soldiers to get ready for the upcoming invasion.

Deborah "Debbie" Grayson is a major character in Invincible, serving as one of the deuteragonists of Season 1 and tritagonists of Season 2 and onward. She is the wife of Nolan Grayson, the mother of Mark and legal stepmother of Oliver Grayson. For two decades, Debbie and Nolan have shared a beautiful affectionate life alongside their son Mark, who would later become the superhero Invincible. Upon uncovering the reality of Nolan's afflictions, she begins to question everything she once understood, grappling with the truth that the man she thought she knew and loved was just a façade, all the while caring for her son Mark and her new stepson Oliver. She later starts a new relationship with her coworker, Paul, while coping with the recent trauma from her encounter with Angstrom Levy.

Jack, also known as Samurai Jack or simply the Samurai, is the alias taken by a Japanese warrior prince; with an unknown birth name; who acts as the titular protagonist of the cartoon, Samurai Jack. Since youth, Jack trained in many different areas under numerous teachers in a variety of skills and wielded his father's magical sword to defeat the demon Aku. However, Aku's time travel spell sent Jack eons into The Future, where he ruled all of Earth unopposed. Jack made it his mission to find a way back to his time and prevent Aku's dystopia. Throughout his travels, Jack became an infamous freedom fighter, protecting and aiding numerous civilizations and innocents terrorized by Aku's forces and other malevolent foes. Due to his many revolts against Aku's rule and being the only person capable of killing him because of his divinely crafted sword, he was the most wanted man in the world.

Kratos is the main and titular protagonist of the God of War series. He is a demigod son of his father Zeus and mother Callisto, as well as a brother of Deimos. Kratos is also the father of Calliope and Atreus and was married to Lysandra and Laufey. Once the brutal captain of the Spartan army, Kratos led his men through numerous conquests across Greece, eventually facing the Barbarians. Overwhelmed and on the verge of death, Kratos struck a deal with Ares by committing atrocities under his name. Even his own family grew horrified by his actions. Tragically, Ares tricked him into killing his wife and child, branding him the "Ghost of Sparta" with their ashes fused to his skin. Seeking redemption, Kratos served the other Gods of Olympus for ten years, enduring their labors that deepened his hatred for them. Ultimately, he defeated Ares and claimed the throne of the "God of War", but his fury against the Olympians led to a series of battles that determined Greece's fate. Eventually leaving Greece as well as his bloody past behind, Kratos ends up in Ancient Egypt and makes his way into Midgard. Having come to view his troubled past with great shame, Kratos has taken the initiative to mature and grow past his destructive tendencies, choosing to live as a man under the Norse Pantheon. He even finds love again with a woman named Faye, eventually fathering a son with her named Atreus. When Faye dies of unknown circumstances, Kratos and Atreus set out on a journey to spread her ashes from the highest peak in all the Nine Realms as it was her final wish. However, the two come into conflict with various Nordic creatures along their way and are constantly pursued by a mysterious stranger, seemingly under orders from the King of the Norse Pantheon himself, Odin.

Metro Man, another alien from the Glaupunk Quadrant, a superhero and Megamind's initial arch-nemesis of good. Before the planet was absorbed by a blackhole, his parents sent him off the planet in an escape pod to Earth, where he 'landed' under the Christmas tree of a wealthy human home. Metro Man maintained his heroic facade and inadvertently turned Megamind evil. From this point on, he would frequently fight Megamind, though as described by Megamind and a few others, Metro Man is always victorious. Metro Man adopted his ubiquitous alias later on, prompting Megamind to create that of his own.

Markus Sebastian "Mark" Grayson is the main protagonist of the series of the same name. He is a Viltrumite-Human hybrid superhero Invincible, the son of Nolan and Debbie Grayson, the paternal older half-brother of Oliver Grayson, the boyfriend of Eve Wilkins/Atom Eve. Born as a Viltrumite-Human, Mark would ultimately gain his powers and start training to become a hero under his father's mentorship. Following a short involvement with the Teen Team, Mark teamed up with Atom Eve, the second version of the Guardians of the Globe, and Cecil Stedman from the G.D.A. to safeguard Earth from all known threats, while also attempting to protect Earth and the entire galaxy from the dangers presented by the Viltrum Empire.

This is a heartless imitation of the main superhero, Invincible. He is a vile, cruel conqueror in his universe as he has lived a very different life to our Mark Grayson. Most of his life has been spent with the Flaxans in their dimension and it has left quite an affect on his psyche. Instead of being a symbol of hope and strength, this Mark upholds malice and sadism. The influence of the Flaxans has clearly rubbed off on this Invincible but he is no less dangerous than them.

Samantha Eve Wilkins, better known by her alter ego, Atom Eve, is the tritagonist of Invincible, and the main protagonist of her own prequel story. She is a genetically bioengineered superhuman, and the girlfriend of Mark Grayson/Invincible. Born as the U.S. government's ultimate weapon, she was rescued by her creator, Dr. Elias Brandyworth, at her dying mother's wish and entrusted to the Wilkins family for safety. In her pre-teen years, Eve emerged as a hero with the ability to manipulate matter at a subatomic level. She had been a previous member of Teen Team before they broke up for auditions for the new Guardians of the Globe. While she succeeded in the trials, Atom Eve chose to follow a path as an independent humanitarian hero.

This variation of the Viltrumite hybrid, Mark Grayson, has gone down a far more brutal path than the original one. On his Earth, no one can stand against him as he's completely toppled all the ruling powers and established himself as the dominat force globally. His Viltrumite DNA allowed him to wipe out the heroes of his world with minimal effort and now fear is the thing that keeps the planet spinning. One of the only people he ever genuinely cared about was his universe's William.