Erik Stevens was raised in the United States by his father N'Jobu in Oakland, who promised him that he will see Wakanda one day. One day, Erik was playing basketball with friends until he saw a Royal Talon Flyer above the apartment. Going inside the complex, he found his father dead with panther claws in his chest. Erik cradled his father in tears before getting his father's diary and reading it in detail. 
Erik grew up in poverty and read oppression on African-Americans. Wanting to make his father's dream on Wakanda becoming dominant, he decided to avenge his father and take what was his. At a young age, Erik joined Annapolis and graduated at age nineteen, then went to MIT for grad school. Afterward, Stevens joined the United States Navy SEALs to a JSOC ghost unit, becoming a mercenary who gained the nickname Killmonger for his savagery.
In 2016, Killmonger made a deal with Ulysses Klaue, who found a Vibranium Warhammer in the Museum of Great Britain. The robbery was a success, but Klaue was captured by T'Challa after his fail attempt to sell the vibranium to Agent Everett Ross in South Korea. Realizing this, Erik rescued Klaue from T'Challa, Okoye, Nakia, and Ross.
- "I'm exercising my blood right. I challenge for the mantle of king and Black Panther."
- ―Erik Killmonger
Even though Killmonger had worked with Ulysses Klaue 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. 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, one which T'Challa accepted.
Before the duel began at the Warrior Falls, Killmonger took his shirt off, bearing his scars, stating that each scar stood for a life he had taken, lives in the United States of America, as well as Afghanistan and Iraq. Killmonger had the upper hand in the fight, as the duel required the Black Panther to be stripped from his powers in order for the duel to be fair. While T'Challa managed to cut Killmonger, he still lost. Killmonger gravely wounded T'Challa, cutting his thigh and his stomach.
Before he went to give the killing blow, Zuri stopped him. Zuri, having been sent by T'Challa's father, King T'Chaka to America to keep an eye on Killmonger's father N'Jobu and had been there during Killmonger's childhood, begged Killmonger to take his life and spare T'Challa, telling Killmonger the truth of his father's death. In rage, Killmonger killed Zuri by stabbing him in the heart, calling him "Uncle James", and T'Challa screamed in despair for his death. Using T'Challa's vulnerability to his advantage, Killmonger went on to punch the King, mocking him and the fact that he was too weak. In the end, Killmonger picked T'Challa up on his shoulders and threw him down the waterfall to his alleged death, leaving Killmonger to be the new King of Wakanda.
Killmonger goes through the coronation ritual, consuming in the Heart-Shaped Herb and met N'Jobu in the Ancestral Plane. Becoming the Black Panther, Killmonger ordered that the herb gardens be burn downed, going as far to lift a woman by the throat who questioned his command. Killmonger, now the king of Wakanda, is supported by W'Kabi and his Border Tribe army, prepared shipments of Wakandan weapons to be distributed to operatives around the world, so they may spread it to other people of African descent so that they may fight back against their oppressors.
The Jabari Tribe had found T'Challa in the freezing rivers where they fish and brought him back to their domain. M'Baku decided to save his life as repayment for his mercy at the falls earlier. In their displeasure manner, Nakia, Ramonda, Shuri, and Everett Ross escaped Wakanda while Killmonger consolidated his power. With T'Challa comatose and stabilized only by the surrounding snow, Ramonda remembered to use the one Heart-Shaped Herb they stole to bring him back.
Awaking in the Ancestral Plane again, T'Challa was greeted by T'Chaka and invited to join him and the rest of his ancestors. Instead, T'Challa was furious at his father for what happened to his uncle and cousin and angered by the other Black Panthers for how their strict isolationism has led to suffering around the world. T'Challa declared his work wasn't done yet and woke to the relief of his loved ones. T'Challa thanked M'Baku for saving his life and requested that he and the rest of the Jabari help overthrow Killmonger. M'Baku declined, as he had already repaid his debt to T'Challa. The group left the tribe, with Shuri giving T'Challa his Panther Habit for the coming battle.