Invincible Season 4 will include a few characters stronger than Mark Grayson (Steven Yeun). Following an explosive Season 3, the highly anticipated new batch of episodes will further challenge Mark, especially after defeating Conquest (one of the strongest Viltrumites) in the finale. What made things interesting for Mark's journey in Season 4 was his message to his half-brother, Oliver, not to hesitate to kill their enemies if anyone threatened their family.
Some would argue that Mark's new mindset about killing makes him even more dangerous next season, but other characters could bring him back to his senses if he were to lose control of himself. Ahead of Invincible Season 4's premiere in March 2026, these are the characters who could beat Mark in a confrontation.
Thragg
As one of Invincible Season 4's main villains, Grand Regent Thragg of the Viltrum Empire is perhaps the strongest Viltrumite ever, meaning that he is far more dominant and dangerous than Mark Grayson (at his current state of power and training). This is in addition to the fact that he is built as a ruthless killing machine.
Thragg's arrival suggests that Invincible is in the endgame now, considering that Mark needs to unleash his full might (more than what he unpacked against Conquest) to defeat him. Invincible Season 3's finale hinted at how Mark can defeat Thragg because of his dialogue about ditching his no-kill rule when someone threatens their family.
In the comics, Mark held up his own against Thragg, and he ultimately defeated him while they were fighting near the core of the sun in their final battle. Some pointed out that Mark was already far more powerful than Thragg at that point, while the villain was only superior in skill and experience.
Battle Beast
Battle Beast is a recurring villain and anti-hero in Invincible whose main goal is to embrace the thrill of combat. As one of the strongest non-Viltrumite fighters, Battle Beast can still hold his own against Mark, especially after he clashed against the titular hero and the Guardians of the Globe combined in Invincible Season 1.
While he appears to be on the side of the good guys when Invincible Season 4 begins (considering that Allen the Alien recruited him to be part of the fight against the Viltrum Empire), the comics revealed that he would eventually die in the hands of Thragg, the same villain whom Mark defeats in the far future. Given that Thragg killed him, this indicates that the Season 4 villain is stronger than Battle Beast and weaker than Mark, since he goes on to defeat the Grand Regent.
Omni-Man
Although Invincible Season 1 proved that Omni-Man was stronger than Mark after defeating him, this version of the titular hero was still at his most vulnerable stage. Mark defeating the likes of Conquest, alternate evil versions of himself, and Angstrom Levy in the next two seasons means that he is already far stronger than Omni-Man by the time Season 4 begins.
Read more about whether Omni-Man is truly redeemable in Invincible here.
BONUS: Allen the Alien
Allen the Alien received a much-needed upgrade in Invincible Season 3 after enduring a post-regeneration treatment that allowed him to match the strength and intensity of a Viltrumite. Given that Allen can now hold his own against a Viltrumite, he is of equal power or even stronger than Mark when Season 4 begins.
Eventually, though, Mark will surpass Allen the Alien's powers at his prime during the Viltrum War, per the Invincible comics, proving that the titular hero is poised to become a superior fighter than him.
