Zelem can be seen when the player first goes to Zelem's Nexus, in a scene showing him and his Quantum heroes. He's also the only known "Genesis Crogenitor" of the five (Ptyron, Zelem, Astra, Ingto and Suzu) to have his death confirmed.
From the time Zelem arrived on Nakto to the time he vanished, many events occured.
He set up a lab in which members of the indigenous races worked on teleporters to make travel between the Nexus easier and safer. However, Zelem was actually monitoring and observing the effects of radiation exposure on the lab workers.
One day, a mechanic named Vex, the Chrono-Shifter, started up a teleporter device and accidentally teleported himself into the very enclave of Zelem himself. Horrified by the giant grotesque figure standing before him, Vex began warping around the room seemingly uncontrollably, trying to escape. Zelem was fascinated, until Vex destroyed nearly everything in Zelem's hideout and then vanished. Vex then departed from working for Zelem to fight The Darkspore.
Zelem also magnified the powers of an already-quantum hero, Magnos, the Binary Star Sentinel, allowing him to gain power from any source of radiation like cosmic rays, lasers, or plutonium ions. It is currently unknown how other than genetic mutation.
Some time later, Zelem sent out a wave of energy directly from the core of the Nexus. On another isle near the gravitational center of the Nexus, an engineer named Orion was working at the Nexus' power plants when this happened. Everyone but Orion fled the building, and Orion was hit by the energy wave and was given Quantum abilities. He used these abilities as if by instinct to knock two floating islands offcourse that were about to collide, thus saving millions of lives while nearly losing his own. Orion, the lightspeed tempest, then went into hiding after The Darkspore invaded and departed to fight them.
On yet another section of the Nexus, an elite engineer named Andromeda used her gravitic powers to help the people of her home island Mishima. Impressed by her actions, Zelem lead her into his enclave and made her into one of his living weapons there. She learned much from him, and he called her his "child". One day, when The Darkspore sent a fleet to the Nexus, Zelem disappeared. Without her mentor, Andromeda, the Gravitic Warmaster ,was free to do what she wanted to, and so she joined the resistance against The Darkspore.
Sometime after The Darkspore conquered Zelem's Nexus and Zelem was thought to be dead, a burglar named Maldri found Zelem's old lab. Maldri saw all of the machines and weapons, and wanted them all to himself. During his raid, Maldri accidentally activated a ray gun that struck him with a beam that granted him Quantum powers, and he then claimed his title, 'the Quantum Raider'.
After fleeing the inner nexus, Zelem was ambushed by Darkspore in the Outer Rings of Zelem's Nexus, where he was presumably killed.
- Thomas Vu, the Lead Producer of Darkspore, pronounces Zelem's name as "ZEE-LUM". However, Michael Perry, the Executive Producer, pronounced it as "ZEL-LUM" at the PAX Expo.
- For a while before the game's release, Zelem was thought to be the Corruptor, mainly because he was the only known Crogenitor at the time. In the BETA, HELIX mentioned a Crogenitor who's name sounded similar to "Zy-lem", but because Zelem was still the only known Crogenitor at the time, people still continued to beleive he was the Corruptor, even though HELIX mentions in the game that Zelem was bitterly agrieved when he found out E-DNA was being used in Crogenitor laboratories. When it was "Xylan" that HELIX was saying. This news revealed that a 7th Crogenitor, Xylan, existed and became the Corruptor, the confusion was sorted out.
- There are Cashout Items, that have Zelem's Affix. The Affix modifies Maldri's Probability Assault to teleport proximite enemies at the end of its duration.
- Zelem's headgear resembles a popular-culture Viking helmet.
- Zelem initially attempted to recreate the planet Nakto in the sector of the current Zelem's Nexus now known as the Chaos Fields.
- The Floating Isles sector in the Nexus could possibly contain one of Zelem's laboratories as, according to HELIX, it was there that Zelem collected specimens for his experiments.
- Accoring to HELIX, Zelem was the leader of opposition against E-DNA experiments. This could possibly be the reason why Zelem was the first Crogenitor casualty of the Mutation Wars.