Onyankopon is a supporting character in Attack on Titan The Final Season Part 2 who serves as a pilot and faithful ally of the Scout Regiment on Paradis Island. He comes from an unidentified nation that was invaded and conquered by the Marleyan Empire during a war, after which his homeland ceased to exist as an independent country and its lands were absorbed into Marley. Forced into service, he became a soldier in the Marleyan military before joining the Anti-Marleyan Volunteers, a group operating under Zeke Yeager. His central motivation was the belief that helping Zeke would bring freedom to the nations that had been crushed and annexed by Marley, including his own. He was among the Marleyan soldiers aboard the first survey fleet sent to Paradis Island after Marley's failed attack, and he later chose to stay with the island's forces and support their cause.

In appearance, Onyankopon is a dark-skinned man of sturdy, broad-shouldered build with short black hair, and he typically wears a Marleyan military uniform with two black stripes running down the torso. His name is drawn from the name of the sky god worshipped in his homeland, an origin that fits his most notable ability, as he is a highly skilled pilot of both airships and aircraft. He becomes the primary pilot for the Scout Regiment and plays a vital role in critical operations. During the raid on Liberio, he piloted the airship that allowed the soldiers to retreat, following instructions given by Hange Zoë. He works especially closely with Hange, and the two develop a strong working relationship built on mutual trust, sharing conversations about technology, ports, and airships.

In The Final Season Part 2, Onyankopon frees a group of imprisoned soldiers and helps them get back into action, continuing to support them as a pilot during their desperate mission. His development centers on his idealism being tested by the chaos around him. He originally supported Zeke because he believed the plan would rescue nations subjugated by Marley, but as events unfold, he is forced to reconsider where his loyalty belongs. He remains steady, composed, and dependable, willing to place himself in danger for the people he has come to regard as comrades. Later, he is deeply affected by the loss of Hange, and that grief strengthens his resolve. His journey is that of a man who moves from serving an exiled leader's vision to standing beside the people of Paradis, using his piloting expertise to keep them airborne during their most dangerous moments.