|Because our creator thought, 'It's more interesting with a mix of people.' You Subjects of Ymir are the same. We exist because we were wanted.|
|— Onyankopon's views on different ethnicities|
Onyankopon (オニャンコポン Onyankopon?) is one of the Anti-Marleyan Volunteers working under Zeke Jaeger. He was one of the Marleyan soldiers on board the first scout fleet to Paradis Island after Marley's failed attack operation.
Onyankopon is a brown-skinned man with black hair styled in a short crew cut. He appears to be well-built, as seen by his large arms and shoulders. He wears a military uniform of Marleyan issue with two black harnesses going down the torso.
Onyankopon's casual clothes consist of a navy blue jacket over a white dress shirt, and long pants.
Onyankopon comes off as a friendly man, easily building a rapport with Hange Zoë and other members of the Scout Regiment during his dealings with them. However, he also seems to have a rather serious mindset, becoming slightly perplexed by some soldiers' fixation on trivial matters during their preparations, and praising Hange for easily adapting to the technologies and ideas introduced to Paradis Island.
Onyankopon appears to be a religious man, professing to the Eldians on Paradis who question him about his skin color that he believes God created different ethnicities of people out of a desire to make the world "interesting."
In 851, Onyankopon is among the first survey fleet sent by Marley to Paradis Island after the operation to retrieve the Founding Titan failed. His ship is captured and breached by Eren Jaeger and he and his fellow soldiers are confronted by Hange Zoë, who offers to negotiate with them. When his commanding officer refuses to listen, Onyankopon joins his fellow crew member Yelena in disarming their commanding officers and accepting Hange's offer.
Meeting with Hange and Levi Ackermann, Onyankopon and Yelena allow the two to inspect their weapons, explaining that Marley has not launched a full assault on Paradis Island yet, due to a war they are currently caught in. Hange guesses that they are sleeper agents who have infiltrated the Marleyan army, but Yelena explains to them that they are simply conscripted soldiers who have chosen to rally around Zeke in opposition of Marley as the Anti-Marleyan Volunteers.
Forming an alliance with Paradis Island, Onyankopon and his comrades begin sharing their technology with the islanders, with Onyankopon focusing on ways to strategically prepare Paradis Island for reintegration with the outside world, such as building ports for ships to dock.
In 854, during the Scout Regiment's invasion of Liberio, Onyankopon participates in the retreat of the regiment's troops, serving as an airship pilot and picking up Armin Arlelt first after his destruction of the Marleyan harbor. He follows the lights set up around the internment zone that function as a path for their escape, reassuring Hange of his piloting capabilities. He is left to pilot the airship as Hange leaves to speak with Zeke Jaeger.
After returning to Paradis, Onyankopon and his fellow Volunteers turn over a stock of Titan serums they managed to steal from Marley to the Garrison. After receiving the serums, Dot Pyxis has his soldiers capture the Volunteers, revealing that Paradis is not willing to trust Zeke and his followers yet.
While he is being held in captivity, Onyankopon is visited by Hange. Onyankopon expresses his dismay at the Paradis military for imprisoning the Volunteers, reminding Hange of what the two forces accomplished while working together over the past three years. Hange is similarly unhappy with the predicament, but justifies the military's actions by revealing, to Onyankopon's shock, that Yelena had secretly met with Eren prior to his surprise attack on Liberio. Hange asks Onyankopon for any information he might have about Yelena, and Onyankopon reveals that Yelena was always the Volunteer who would step forward to execute any Marleyan soldiers that might suspect them of treason. Hange notes a seeming discrepancy in Yelena's behavior, pointing out that Yelena also campaigned passionately for Paradis's Marleyan prisoners of war to be treated fairly, which Onyankopon suggests may have been an attempt on her part to atone for her harsh behavior previously. Hange is unconvinced, and orders that Onyankopon accompany them to look into the matter further.
After Dhalis Zachary and other military officials are killed in a bombing at the military's headquarters, Onyankopon accompanies Hange to a hearing with the remaining commanders to discuss the attack. Hange provides the Volunteers with an alibi for the bombing, pointing out that Onyankopon was with them and that the other Volunteers were under house arrest at the time.
Onyankopon accompanies Hange and the other Scout officers as they visit Nicolo to question him. While at the restaurant it is discovered that the wine Nicolo and other Marleyan prisoners have been serving to the military's officials may have been spiked with Zeke's spinal fluid on Yelena's orders. Although Yelena's involvement immediately causes the soldiers to become suspicious of Onyankopon as well, he insists that he had no knowledge of the plan. Onyankopon is then captured by the Jaegerists, who have arrived at the restaurant. The Scouts are taken captive and the entire group is transported to Shiganshina District.
Onyankopon is among the Anti-Marleyan Volunteers who attend Yelena's meeting to accept Dot Pyxis's surrender. Afterwards, he accompanies Yelena to visit the Scouts in their holding cells. Tensions are high between the prisoners and Onyankopon, and when Jean Kirschtein tries to deduce what their true intentions are with Paradis, Onyankopon unhappily reminds the prisoners that the volunteers were the ones who helped "civilize" the island. When Greiz interrupts their conversation to insult Nicolo, Onyankopon is horrified to see Yelena shoot him in the head. He then assists in removing Greiz's corpse from the hall as Yelena continues to explain Zeke's intentions to the prisoners. Soon after, a Jaegerist arrives informing them of Infiltrators. He accompanies Yelena to the roof where a captured Warrior claims that she will point out her own allies. However, she double crosses them and Eren is ambushed by the Jaw Titan, nearly killing him. Onyankopon is caught speechless as a number of Marleyan airships descend from the sky.
- Nyankopon (alternatively spelled Onyankopon) is one of the names of the Creator God in the Akan religion.
- Onyankopon bears a strong resemblance to real-life British actor John Boyega.
- Boyega is a noted fan of Attack on Titan and has acknowledged the similarities between himself and Onyankopon on several occasions.