Mark Antaeus was the son of a scientist who injected him with experimental growth hormones giving him super-human agility, strength and endurance. Mark Antaeus looked up to Superman to the point that he had a large 'S-shield' tattoo across his back. He was featured in a 1999 JLA One-Shot, and hasn't been shown since.
Mark Antaeus had a girlfriend, mother, and a father, and was similar to Superboy , since he had Super-Strength and Durability, but was limited to jumping far distances rather than flying. After failing to save four citizens, Mark became depressed and soon resorted to getting implants from S.T.A.R Labs to augment his powers and abilities, and had energy blasts, as well as fire blasts, and could fly with powerful jets. He was soon recruited to the JLA, but, after going on a rampage and killing a terrorist who threatened to kill a mother and children, he neutralized, or rather violated the JLA rules and killed the terrorist to save the people. However, he stated that he had already quit the JLA, and was angry at them for not taking action. Mark stalemated, and even gained an upper hand at fighting JLA (Superman, Wonder Woman, Martian Manhunter, Batman , Kyle Rayner, Aquaman, Wally West) after being enraged. However, after he escaped, he found out that he did more harm than good (the country went into complete chaos, and many innocents died) and committed suicide by disrupting his power suit, and flying/damaging it so that it self-destructed.
Powers & Abilities
Energy Blasts - After augmentations, his suit could fire powerful blasts in which he used against enemies and the JLA alike.
Fire Blasts - After augmentations, he used this against Martian Manhunter, knowing he was afraid and/or had a weakness to flames.
Gravitational Control - After augmentations, Mark used this against Flash to disable him and make him "fly" away.
Super-Strength - Although Mark had this before augmentations, it was greatly enhanced after. He could fight against the strongest DC Heroes, such as Wonder Woman and Superman.
Durability - The toughest blows from even Superman could not dent his suit, although when the Flash hit him, it temporarily disrupted his suit's functions. He did not show any sufficient damage to the suit until his suicide.
Flight - Before augmentations, Mark could only leap in strong bounds, but after augmentations, he could fly with power boots.