Shūji Miwa and Yōsuke Yoneya vs. Koskero

Shūji Miwa and Yōsuke Yoneya vs. Koskero is a fight between Shūji Miwa, Yōsuke Yoneya and Koskero that happened during Galopoula's Invasion.

Prologue
Galopoula's forces attack Border under Aftokrator's orders. A team of snipers are sent to the rooftop of Headquarters to hold off the large wave of Idras. However, they are quickly overwhelmed by someone sending Dogs to the roof. At Arashiyama's command, Yoneya and Miwa go looking for the one who is behind this action.

Battle
Miwa and Yoneya are quick to find Koskero. Koskero laments that he ended up getting some strong opponents, referring to him having seen Yoneya fight before. Yoneya is quick to go on the offensive, immediately striking Koskero, however he blocks his attack. Miwa shoots at him, but Koskero uses one of the Dogs to block the shots. He skillfully dodges Miwa's Kogetsu and takes Yoneya's spear out of commission by covering it with Nikokyra. Not quite realizing this yet Yoneya goes to attack incoming Idras with his covered blade but finds he can not cut through anything. This allows the two teens to figure out what Nikokyra's function is.

Yoneya manifests another Kogetsu out of his subtrigger while Miwa hinders the Idras with his Lead Bullet, allowing Yoneya to make quick work of them. He then strikes Koskero once again. Koskero guards, however Yoneya has a trick up his sleeve: Gen'yō. The blade goes around Koskero's arm and slices his leg off. Koskero calls Yomi for a change in the Idras attack pattern, and declines his request to join battle alongside him.

Wen Sō is taken out by Nasu, and Koskero comments that Meeden is very strong before covering Yoneya's left hand and foot with parts of Nikokyra. Yoneya now can not hold his spear with two hands, and Miwa notes that Nikokyra works like Lead Bullet. The battle moves into a nearby house, where Miwa and Yoneya discuss Koskero's defensive stance. Yoneya compares Nikokyra to Hyrein's Alektor, and destroys the ceiling with Senkū Kogetsu. Koskero realizes that they know how Nikokyra works, and moves outside the house to gain an advantage.

Miwa has other ideas. He asks Koskero about his sister, and if he knew which nation killed her. Koskero quickly attacks them with Nikokyra again, rendering Miwa unable to hold his Kogetsu, before telling them that he has no obligation to answer that question and that they should not be talking during battle. However, this is all part of Miwa's plan. Fūjin blades race across the Forbidden Zone and rip through Koskero's trion body, rendering him unable to continue fighting. Jin then leaves the scene to pursue Yōtarō and Hyuse.

Miwa and Yoneya say they will escort Koskero back to the base. However, the Galopoula soldier bails out, leaving the two empty handed.