Gladiator

Track Record
When Worlds Collide tournament - Won first round in tag team with Professor X, beating Black Adam and Metamorpho

History
Gladiator's history before he joined the Imperial Guard is largely unknown. On one occasion Galactus mentioned a being that seemed to match Kallark's description as a former herald.[1]

He became a fiercely loyal and powerful member of the Guard, personally trained by Deathbird, and was named Praetor. Regardless of the Majestor or Majestrix in charge, Gladiator would heed their orders.

He was one of the Guard members chosen to battle the X-Men over the fate of Jean Grey, who had become the Dark Phoenix.

Kallark was later charged with pursuing a group of Skrulls posing as a superhero team. He believed the Fantastic Four to be this group and attacked them. Captain America and Spider-Man found the real Skrull group and assisted in their capture.

Kallark was among a number of Imperial Guard members temporarily relocated to Earth. After learning of a Phalanx invasion of Shi'ar space he confronted Cannonball, sending him, the Beast, Trish Tilby, Joseph and Rogue to assist in his stead.

At another point[2], Kallark was enlisted by Pip the Troll to try and liberate the planet Skardon from the apathetic rule of the Champion of the Universe (because Skardon law would not recognize the legitimacy of any challenger unless they could beat the Champion in a boxing match). Kallark fought against the Champion, but lost because the Champion possessed the Power Gem which allows it's wearer access to all the power that has or will exist. Kallark spent a period of time recuperating from his injuries; meanwhile, She-Hulk convinced the Champion to remove the Power Gem, and subsequently pummeled him into submission.

Most recently Kallark was sent to Earth to find the Uni-Power, which was traveling from host to host for help against Krosakis. He found it with the Invisible Woman, and was able to convince it to come with him.

Krosakis attacked Kallark and the Uni-Power as they left Earth. The Silver Surfer intervened and returned the Uni-Power to Earth while Kallark took Krosakis into Shi'ar custody.

Gladiator was able to effortlessly defeat Vulcan after several other members of the Guard were killed or seriously injured attempting to capture him.

Gladiator is presumably still praetor of the Imperial Guard under Emperor Vulcan's rule.

Powers
Superhuman Strength: Gladiator possesses tremendous physical strength, the exact limits of which are unknown. He is one of the physically strongest beings to exist in the Universe as he has shattered planets with the mere force of his blows, and can collapse entire Stars with his level of strength. His strength level is dependent on his confidence; as such the more confident he is, the stronger he gets. He has demonstrated several astounding feats of strength such as defeating Colossus with relative ease, almost matching Hulk strength in battle, overpowering Hyperion, and even managing to hold his own for an extended period of time against Thor. Hence, Gladiator is ultimately able to lift somewhere far in excess of 100 tons.

Superhuman Speed: Gladiator is capable of running and moving at speeds vastly greater than even the finest human athlete. While the exact limit of his speed is unknown, he is able to move considerably faster than the speed of sound, which is roughly 770 miles per hour. Gladiator is capable of moving at speeds in excess of light. The level of his speed depends on his confidence.

Superhuman Stamina: Gladiator possesses extraordinary physical stamina. His muscles generate considerably less fatigue toxins then the musculature of human beings or most other known beings for that matter. Gladiator is able to exert himself at peak capacity for at least several days before the build up of fatigue toxins in his blood begins to impair him.

Superhuman Durability: Gladiator's bodily tissues are much tougher and far more resistant to physical injury than those of human beings. He can withstand high caliber bullets, survive in space unaided, powerful concussive blasts, falls from tremendous heights, and blows from powerful superhumans such as the Hulk without sustaining injury. Gladiator is also highly resistant to extreme temperatures, particularly intense heat. He has shown himself to be capable of flying through stars completely unharmed, and has actually withstood the explosive power of a supernova unharmed. The level of his durability depends on his confidence.

Superhuman Agility: Gladiator's natural balance, agility, and body coordination are enhanced to levels that are beyond the natural physical limits of even the finest human athlete.

Superhuman Reflexes: Gladiator's reflexes are similarly heightened and are superior to those of the finest human athlete.

Flight: Gladiator is able to generate gravitons that enable him to fly. Gladiator's flight speed rivals those of the fastest known starships, and can achieve faster than light speeds in hyperspace.

Heat Beams: Gladiator is capable of firing highly concentrated beams of energy from his eyes. These beams are capable of reaching extremely high temperatures. The maximum temperature his beams can reach is unknown but they can reach temperatures hotter than that of Stars as they were shown able to burn through Hulk's skin. The temperature level of his heat beams depends on his confidence.

Microscopic Vision: Gladiator possesses the ability to see extremely small objects and images beyond sub atomic level.

Super Breath: Thanks to his incredible lung capacity, Gladiator is also able to draw in large amounts of air and then expel it all to create gale and hurricane force winds. He can also chill his breath to freeze targets. Psi Resistance: Gladiator is capable of causing a counter-force against telepathic assaults and probes. However, telepaths of sufficient power are capable of penetrating his psionic defenses to an extent.

Abilities
Gladiator is highly skilled in the combat arts of the Shi'ar, personally trained by Deathbird.

Strength
Gladiator possesses Class 100 superhuman strength, enabling him to lift (press) far beyond 100 tons.

Weaknesses
Gladiator is vulnerable to a certain specific wavelength of radiation. A significant portion of Gladiator's powers, especially his strength, stamina, and resistance to physical injury, are affected by his level of confidence. If his confidence in himself wavers, he has been known to weaken substantially.

Equipment
Gladiator carries a Shi'ar device that helps stabilize massive objects that he lifts. He may have other devices that contribute to his powers.

Transportation
Flight under his own power; access to Shi'ar starships and star-gates.

Trivia

 * The character's powers are considered to be inspired by those of Superman, though they might also be inspired by Mon-El from the Legion of Superheroes (most of the Imperial Guard members created by Dave Cockrum were based on Legionnaires.) The name Kallark is a combination of "Kal" and "Clark", the two aliases of Superman. The name Gladiator could have come from the novel Gladiator by Philip Wylie.