- "Demon Lord, what is it you hope to achieve on the battlefield?"
- ― Kupchenko to Cipher.
In his early days in the Belkan military, he fought on various battlefields and wars involving his homeland, earning the nickname "The Gold Woodpecker". As a result of his experience in the engineering field, he joined the Belkan Army's weapons & technology research department in the 1970s, being the chief engineer of Project Pendragon. In 1988, the Belkan Federal Law Review caused the nation's economy to collapse, thus leading to the end of Project Pendragon. However, Kupchenko remained with the Belkan Air Force. 
- "The table is surrounded by politicians who have never placed a foot on the battlefield. It's a disgusting squabble over who gets the largest piece of the pie, and that's why it needs to end. It is for that duty we raised the King. That's why we're fighting."
- ― Kupchenko describing his motivation to fight.
In January 1994, as the Belkan Federation planned on expanding its territory, he became the leader of Gault Team. During the early days of the Belkan War in March 1995, Anton and the Gault Squadron unexpectedly disappeared from the skies, leading the military to mark them all as killed or missing in action . It is believed that Kupchenko founded the paramilitary group "A World With No Boundaries" alongside his wingmen. 
In December 31, 1995, the military forces of Ustio and Osea launched an assault on Avalon Dam after AWWNB's XB-0 Hresvelgr was shot down by Galm Team, a missile facility disguised as a dam in Nord Belka, in order to stop AWWNB from launching a V2 missile, itself targeting many of the world's capitals. Galm Team launched from Valais Air Force Base in their final sortie. They reached Area B7R, serving as a shortcut for the mission, on their way to the dam, only to be ambushed by Anton Kupchenko and the Gault Team. The Galm Team eventually gained the upper hand, and the entire Gault Squadron was eliminated. 
- "The gate to the new world has been opened. My soul shall be the wind that enters the gate. When the sleeping king awakes, my body, too, shall surely rise."
- ― Epitaph on his tombstone.
Kupchenko was skilled in flight and military engineering, becoming the chief engineer of Project Pendragon. He was patriotic to his homeland, especially honoring the Knights of the Round Table, despising politicians for their "disgusting squabbles" and having "never placed a foot on the battlefield", leading him to be part of "A World With No Boundaries".