The Age of Apocalypse is one of the grimmest time periods the X-Men have ever endured. In this alternate world where Charles Xavier was killed by his misguided Omega-Level mutant son, most of Marvel's mutants were reinvented in a new dark light. Although the world is still technically part of Marvel's wider multiverse, the original Age of Apocalypse ended with that reality seemingly collapsing in on itself. However, a handful of survivors made it into the main Marvel Universe.

One of these terrifying mutants was Apocalypse's son Nemesis, who would come up against plenty of heroes before even gaining his Marvel Universe counterpart emerged as a threat in his own right.

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Having taken the names Nemesis, Dark Nemesis and Holocaust, the dark mutant murderer was a major figure in the Age of Apocalypse from his debut in Scott Lobdell, Mark Waid, Roger Cruz and Steve Epting's X-Men: Alpha #1 in 1995. Known around the world as the son of Apocalypse, Nemesis established himself as one of his father's most deadly and dedicated Horsemen and helped him lay waste to nations like Japan and wiping out countless innocent lives in the process. He was ultimately chosen for a mission to destroy the burgeoning X-Men under the command of Magneto, which the sadistic young mutant reveled in.

Although the attack successfully resulted in the deaths of multiple young mutants (including Magneto's daughter Scarlet Witch, who'd remained behind to protect the young students), Nemesis ended up being hunted down and seriously injured by Magneto in revenge. With his body broken in the fight, Nemesis was forced to be given a new armored form by Dark Beast. Trapped in the armor, the villain quickly became an even more dangerous one of Apocalypse's agents. Confronting X-Man during the final battle of the event, Nate Grey was forced to stab him with a shard of the M'kraan Cyrstal, which resulted in both of them being ripped into the main Marvel Universe.

Eventually discovered in a state of suspended animation by the Acolytes, Nemesis was brought into Avalon. After awakening and confronting Exodus, their fight quickly led to the fall of Avalon. The villain became a reoccurring threat in the universe, fighting the X-Men, X-Force, and even facing off with the Avengers at one point. Nemesis was eventually forcibly recruited to the reality-hopping Exiles and quickly tried to rebel against the Timebreaker, even reluctantly working with his fellow Age of Apocayplse survivors Blink and Sabertooth. This resulted in them unleashing the demented version of King Hyperion, who quickly used his powers to drain his bio-energy and kill the villain.

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Although he was successfully destroyed, another version of Apocalypse's son exists in the main Marvel Universe too. William Rolfson is the son of Apocalypse and Autumn Rolfson (who previously served as his Horseman of Famine). Fearing that he would be killed by his father if his existence was discovered, Famine went into hiding with him. William naturally produces powerful radioactive plasma energy and requires the use of specially designed robotic armor. He was eventually discovered and recruited by Archangel after he fully transformed into the Dark Angel during Uncanny X-Force. Taking the name Genocide, William even helped set off the events of the Apocalypse Wars and took on Magneto and Psylocke before eventually falling in battle.

While Apocalypse may have other children, Nemesis and his prominence during the Age of Apocalypse and the later half of the '90s have given him a firm place in the X-Men's history. Even if his accomplishments are relatively scant, he will always be remembered the son of Apocalypse.

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