History Main / RivalTurnedEvil

* ''Literature/FengshenYanyi'': Shen Gongbao, introduced [[RememberTheNewGuy during Jiang Ziya's first return trip on Kunlun]], was Ziya's co-disciple and studied alongside him, making more progress on the path of magic. However, he thinks that Jiang Ziya's task of helping the Zhou Dynasty against the corrupt Shang one is a fool's errand and that King Zhou should be the legitimate ruler of the land, despite having being forsaken by Heaven for his empiety and cruelty. He tries to bully his younger friend into giving him the Fengshenbang (the list of the 365 illustrious characters who'll become gods after the war) and joining the Shang, using his greater mastery of sorcery to make him comply. Even when he's thwarted but spared thanks to Ziya, Shen Gongbao swears revenge and spends the rest of the novel spreading lies and deceit to make otherwise neutral or uninterested Immortals attack the city of Xiqi and the forces of Zhou. After finally killing Jiang Ziya (who gets better, as he was [[DisneyDeath destinated to die seven times]]) he's finally captured but spared on the condition that he stops pestering the forces of Xiqi. He breaks his oath siding with the Jie Taoists during the great war at the Ten Thousands Immortals Formation and pays with his life.

* ''ComicBook/TheWarlordDC'': Danny Maddox grew up in the same town as Morgan, and always felt in Morgan's shadow, and blamed Morgan for everything that went wrong in his life. (This rivalry was almost entirely one way, with Morgan barely knowing that Maddox existed). His attempts to beat Morgan drove him deeper and deeper into evil acts. Maddox was the pilot responsible for shooting down Morgan's plane and causing him to crash in the LostWorld of Skataris and, years later, Maddox would descend into Skataris himself in am attempt to prove his superiority to Morgan once and for all.

* ''ComicBook/{{Wolverine}}'': In ''ComicBook/Origin2001'', Dog starts out as James Howlett's friend [[spoiler:and secret half-brother]], but eventually they drift apart, and Dog even kills James' puppy. James eventually runs away from home after an incident causes the death of his parents and Dog's father, and Dog tells the locals it was James' fault. Years later, Dog is told to track James down so that James' grandfather can make amends, but instead Dog tries to kill James for taking his name (Logan). This one also works for TwoGuysAndAGirl, with James, Dog, and Rose. Dog is later tracked down by Sabretooth, Logan's ''other'' rival turned evil when he ends up in the present and is hired as a teacher at the Hellfire Academy.