|Our creator had a thought. Wouldn't it be interesting if there were more kinds of people in the world? The same goes for the Subjects of Ymir, who can turn into Titans. All of us exist because someone meant for us to exist.|
|— Onyankopon's views on different ethnicities|
Onyankopon (オニャンコポン?) is one of the Anti-Marleyan Volunteers and aids the Survey Corps during the Battle of Liberio. He pilots an airship following orders from Hange Zoë for the Corps to use during their retreat.
Onyankopon is a dark-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 stripes going down the torso.
Onyankopon's casual clothes consist of a dark jacket over a dress shirt, and long pants.
Onyankopon comes off as a friendly man, easily building a rapport with Hange Zoë and other members of the Survey Corps 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 being introduced to Paradis Island.
Onyankopon appears to be a religious man, professing to Paradis Islanders that question him about his skin color his belief that God created different ethnicities of people out of a desire to make the world "interesting."
When Onyankopon's home country was taken over by Marley, he was one of many who forcibly conscripted into the Marleyan army to serve as a soldier.
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 beached by Eren Yeager, where he and his fellow soldiers are confronted by Hange Zoë, offering 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 Ackerman, Onyankopon and Yelena allow the two to inspect their weapons, explaining that Marley has not yet launched a full assault on Paradis Island 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 her that they are simply conscripted soldiers who have chosen to rally around Zeke Yeager 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 Survey Corps' invasion of Liberio, Onyankopon participates in the retreat of the regiment's troops, serving as an airship pilot and picking up Armin 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 Yeager.
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 Pixis has his soldiers capture the Volunteers, revealing that Paradis is not yet willing to trust Zeke and his followers.
While he is being held in captivity, Onyankopon is visited by Hange. Onyankopon makes no effort to conceal his dismay at the Paradis military for imprisoning the Volunteers, reminding Hange of all that 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 her to look into the matter further.
After Darius Zackly 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 her and that the other Volunteers were under house arrest at the time.
After another hearing is held to discuss the rogue faction of soldiers being led by Eren, Onyankopon accompanies Hange and the other Survey Corps officers as they visit Nicolo to question him. While they are waiting to speak with him, they discover Nicolo threatening and attempting to kill the two Warrior Candidates that were brought to Paradis, and are forced to diffuse the situation.
- Yelena - One of the other high ranking members of the Volunteers, Onyankopon is on fairly good terms with Yelena. He has noted, though, that she is capable of incredible changes in character and is somewhat troubled by how far she is willing to go to achieve her goals.
- Hange Zoë - Onyankopon has been on good terms with Hange since his arrival on Paradis. The two have worked together to considerably increase Paradis' technological advancements and, despite not appreciating Hange holding them under house arrest, share a mutual respect towards each other.
- Nyankopon (alternatively spelled Onyankopon) is one of the names of the Creator God in the Akan religion.