[1] The character is a Strontian, and like others of his race has the capacity for great strength and various superpowers, but can only use them when he is completely devoted to a purpose; his abilities vary in accordance with his level of confidence.

He has played important roles in some of Marvel's major storylines, such as Operation: Galactic Storm (1992), Maximum Security (2001), and War of Kings (2009).

[7] When the X-Men come into conflict with the Shi'ar empire regarding the Phoenix entity, Gladiator battles them first at the command of Emperor D'Ken,[8] and then at the behest of his successor, Empress Lilandra Neramani.

[14] Deathbird commands him to lead the Imperial Guard against the space pirate Starjammers and superhero team Excalibur, but orders a retreat after learning the rebels are led by Lilandra.

[17] Along with Beta Ray Bill, Ganymede, Jack of Hearts, Silver Surfer and Terrax the Tamer, Gladiator is captured by Tyrant with the intention of harnessing their power as a weapon for universal domination.

[21] After thwarting an assassination attempt on Lilandra,[22] Gladiator plays a role in temporarily turning Earth into an intergalactic prison.

[32] A Shi'ar agent, however, wishing a return to the days of D'Ken's rule, frees Vulcan and together with Deathbird the pair stage a coup and usurp Lilandra.

[33] Vulcan consolidates his rule over the Shi'ar - with Gladiator reluctantly assisting - as their forces destroy a race of ancient enemies, the Scy'ar Tal, and capture the rebel Starjammers.

[41] With them, he protects Galador from the Dire Wraiths[42] and opposes the Universal Church of Truth's attempt to revive the Magus.

[44] During the Avengers vs. X-Men storyline, Gladiator attempts to contact Kubark's bodyguard Warbird about the Phoenix Force's return to Earth.

[46] In the aftermath of the "Infinity Wars" storyline, Gladiator and the Shi'ar Empire arrive to save everyone after they were ejected from a hole in the space station following the Black Order stealing Thanos' body during the funeral.

[48] Gladiator possesses a number of superhuman capabilities as a result of his unique alien physiology including superhuman strength (capable of shattering a planet,[14] ripping apart a black hole, and holding off the Destroyer armor[49][50][51]), superhuman speed, stamina and durability (capable of withstanding the heat emitted from the Phoenix Force, a blast comparable to the full power of Odin, direct attacks from Thor and Mjolnir, point blank planetary explosions, and an explosion equivalent to a supernova[52][49][53]), reflexes, microscopic and telescopic vision,[54][55] X-ray vision,[56][57][58] heat vision (stated as "hotter than a star");[59] super-breath,[53] "frost breath",[49] super-hearing (capable of hearing sounds from light years away in space),[58] a regenerative healing factor,[60] psionic resistance (capable of withstanding mental attacks from telepaths to a certain degree),[61] and warp speed flight (measured as "a hundred times the speed of light",[53] and shown moving across galaxies before Heimdall could blink).

[62] Gladiator's abilities increase and decrease in accordance with his level of confidence[63] and he is vulnerable to a certain form of rare radiation.

[65] In the alternate universe title Marvel Zombies 2, the character appears with other extraterrestrial beings "recruited" by the Galacti (the original infected heroes empowered by devouring Galactus).

[67] In the alternate universe title Last Planet Standing, Gladiator appears with the Imperial Guard but fails to stop Dominas the Wavemaster and Galactus from destroying the Shi'ar homeworld.