He is a ruthless Wakandan warrior, former American black-ops operative and a terrorist leader. Killmonger's father was once a Wakandian citizen who was exiled with his family by Wakanda's former king, T'Chaka, thus Killmonger seeks not only vengeance but also to overthrow T'Challa and conquer Wakanda and the entire world with vibranium to Wakanda's spy network.
To that end, Killmonger has honed his body and mind to the peak, being an expert martial artist, an excellent hand-to-hand combatant, and a genius in a wide variety of fields. He is willing to team up with Ulysses Klaw, as they both have a common enemy in T'Challa.
Erik Killmonger was born many years ago in Oakland, California with the birth name N'Jadaka. His father, N'Jobu, was the prince of Wakanda who was sent to the United States as an undercover agent and would tell N'Jadaka stories about Wakanda, promising the young boy that he would one day take him there, claiming that the sunsets there were the most beautiful in the world.
One night, N'Jobu's brother T'Chaka tracked N'Jobu to his apartment and confronted his brother when N'Jobu was accused of selling Vibranium to terrorists. After N'Jobu's partner Zuri, revealed to be a spy sent by T'Chaka, confirmed this, T'Chaka decided to take N'Jobu back to Wakanda to face judgement for his crimes; but N'Jobu attempted to shoot T'Chaka instead, and in self-defense, T'Chaka kills his brother by stabbing him with the claws of his suit. Outside, N'Jadaka was playing basketball with his friends and caught sight of T'Chakka and Zuri departing on their ship over his apartment building. Rushing back inside, N'Jadaka found his father dead, and was left to mourn his father's death.
Years later, N'Jadaka joined the American military forces, where he has served as a black ops soldier. Thanks to the military, N'Jadaka has gained various skills in combat, martial arts, firearms, weapons and knowledge about explosives and psychological warfare.
After the army, N'Jadaka went on to lead a group of mercenaries and criminals, choosing the supervillain codename "Erik Killmonger" due to his ruthlessness and brutality. Eventually, Erik formed an alliance with Ulysses Klaw to gain access to Wakanda and vibranium.
The two stole a Wakandan weapon made of Vibranium within the Museum of Great Britain. Klaw would later go to attempt to sell the weapon to Agent Everett Ross in South Korea. However, T'Challa, along with Okoye and Nakia intervened on their hunt for Klaw. When the Wakandans finally managed to capture Klaw, after thirty years of trying to find him, Killmonger and his group saved the arms dealer. During the short fight, the Wakandan Royal Ring belonging to his father N'Jobu, which Killmonger kept on a chain, dangled around his neck. T'Challa noticed the ring, as the ring belonging to the King of Wakanda was an identical one.
Even though Killmonger had worked with Ulysses Klaw and had also rescued him, he ended up shooting and killing him in order to gain the Wakandan's trust. Killmonger brought Klaue's body to Wakanda and presented it to W'Kabi, T'Challa's friend and head of border security. W'Kabi, already disappointed with T'Challa for not managing to bring Klaue to justice for his crimes, brought Killmonger to the King and his council.
Killmonger began taunting T'Challa upon first meeting him. He then said that he wanted to be King of Wakanda, and revealed his true identity in anger when T'Challa ordered him to be removed after T'Challa had told Killmonger that the only reason he was still alive was because he knew who Killmonger truly was. Killmonger then challenged T'Challa to a duel, which T'Challa accepted.