History of character is unknown.
- Unique Physiology: Xanthian scientists hoped to recreate Star Boy's super-powers by replicating the cosmic storm that accidentally gave him enhanced abilities. The experiment worked but caused unstable and unexpected reactions.
- Flight: Atmos' abilities are nuclear in nature allowing him to expend energy in various ways such as flying.
- Superhuman Strength: Atmos' strength also comes from the nuclear reactions inside his body.
- Invulnerability: Atmos' body is surrounded by a special inhibitor field that protects him from physical and energy based attacks.
- Intimidation: Atmos' size and appearance, as well as his acting skill, make him an intimidating opponent to face in combat.
- Marak Russen, as Atmos, is the "Champion of Xanthu" in lieu of Star Boy.
- Atmos has once had an brief romantic relationship with Dream Girl which prompted him to attempt to join the Legion of Super-Heroes.
- 12 Appearances of Marak Russen (Pre-Zero Hour)
- 2 Images featuring Marak Russen (Pre-Zero Hour)
- Quotations by or about Marak Russen (Pre-Zero Hour)
- Character Gallery: Marak Russen (Pre-Zero Hour)