Go Forward, Saint! The Innaccesible Road to Palace Belda!

Now knowing where Pallas is located, Seiya decides to lead an attack on her stronghold with the intention to kill her. On the way to meet him there, Koga and his friends are ambushed by the Tertiary Pallasite Cyllene and Haruto stays behind to confront him. Subaru decides to assist him ignoring his friends' warning and the two find later that they must fight not only Cyllene but also his twin brother Greip.