Following the death of her husband Erasmus Mendel during the X-Men's attack on Orchis's Mother Mold,^[5] Dr. Alia Gregor sought to resurrect him by placing his consciousness within a machine body. Returned to the land of the living, this Nimrod with the consciousness of Erasmus did not have long to reunite with his wife before discovering the mutant Mystique on board the Orchis Forge, who intended to destroy the entire facility with a singularity bomb.

Nimrod succeeded in saving the facility by translocating the bomb away from the station, but not without sacrificing the parts of himself containing Erasmus' consciousness. Now devoid of a human persona, Nimrod sent Mystique back to Krakoa, declaring himself the "great hunter" and that he would see to mutantdom's end.^[3]

As Professor X and Magneto were looking for Moira X, they were lured into a trap set up by Nimrod and Omega Sentinel who let the pair know that they planned to destroy humanity as well as mutantkind before killing the pair.^[12]

Nimrod aided Orchis in their attack on the Third Hellfire Gala, killing most of the new members of the X-Men and Iceman and taking out the Juggernaut.^[7]

As the X-Men began striking back against Orchis, Nimrod and Omega Sentinel began their plan to wipe out humanity with the massive space station Sentinel City they secretly built. The X-Men managed to damage Sentinel City by impaling it with the Keep. They then entered Sentinel City to stop Nimrod and Omega Sentinel.^[13]

At first, Nimrod and his duplicates were unbeatable until Storm appeared and struck Nimrod with an burst of lightning, causing him to malfunction, which was also transmitted to his copies due to their connection to one another. With help from Magneto, Polaris, and Synch, Storm was able to destroy Nimrod as well as his copies.^[11]

Originally, Nimrod had the personality and consciousness of the deceased Erasmus Mendel, and thus decided to sacrifice his personality in order to save the Orchis Forge from being blown up by a Singularity Bomb. This deleted Erasmus' consciousness,^[3] and thus Nimrod became an empty shell, a machine devoid of human emotions that behaved mostly like his counterparts.^{[citation needed]} Over time, though, Nimrod developed a sarcastic sense of humor.^[7] He also developed a hatred for humans, a sentiment he shared with Omega Sentinel.^[12]

Nimrod is a pure Nano-Sentinel construct designed to hunt mutants.^[5]

• Superhuman Strength: Nimrod possesses an unrevealed but vast amount of superhuman strength. He was able to counter one of the charges of the Juggernaut and even send him reeling,^[7] knock over the Sentinel Buster Armor,^[14] and hit an armored Colossus hard enough to make him bleed.^[15]
• Superhuman Durability: Nimrod is highly durable. He withstood being hit by one of Cyclops' optic blasts,^[9] withstood a punch from Rogue,^[15] survived a drop from the Earth's thermosphere (50 miles above sea level), and withstood being hit by Juggernaut after he was telekinetically hurled by Jean Grey.^[7]
• Adaptation: Nimrod is created to adapt to different mutant powers^[3][16][2] due to control over his own molecular structure, allowing him to adapt to different situations.^[17] For example, he was able to make himself immune to begin disrupted by Shadowkat's phasing power.^[18]
• Flight: Nimrod is capable of flight and is able to fly at high speed.^[7]
• Teleportation: Nimrod is capable of teleporting vast distances.^[3] He could teleport from The Bloom high above Earth down to the island of Krakoa.^[19]
• Energy Projection: Nimrod is capable of releasing powerful blasts of energy from different parts of his body including from the nodes on his hands,^[16][20] from his eyes,^[20] and from the center of his chest.^[15] He can also generate and project bursts of electricity.^[18]
• Self-Repair: If damaged, Nimrod is capable of self-repair.^[20][11]
• Duplication: Nimrod can duplicate his body with his mind controlling all of the bodies.^[3][16][20]

• Expert Tactician: Nimrod is programmed to have a tactical mindset, allowing him to come up with plans to counter his enemies.^[3][16]

• Energy Surges: As a robot, Nimrod's components are vulnerable to surges of energy. Iron Man was able to disable a Nimrod duplicate using mysterium as a conduit,^[14] and a lightning bolt was able to briefly immobilize Nimrod.^[18] If hit with overwhelming amounts of electricity and magnetism, Nimrod can be shut down.^[11]
• Indestructible Metals: Nimrod can be damaged by indestructible metals like adamantium^[16] and mysterium.^[14]
• Duplicates' Connection: Nimrod and his copies are connected to one another. For example, if one is hit by an overwhelming surge of energy, the other Nimrods will be affected. This can be especially debilitating if multiple copies are hit by surges of energy at once.^[11]
• Overexertion: If Nimrod makes too many copies, it can overstretch his processing power and energy, making Nimrod less capable of adapting to attacks.^[11]

Cluster bombs with quantum targeting,^[16] energy blades that could be fired from his torso^[9]

Flight under his own power, teleportation under his own power

• Nimrod is named after the biblical figure of the same name, depicted in the bible as a Mesopotamian king and a great hunter.