The Hero Is Overpowered But Overly Cautious, Vol. 6 (manga)

It-s time for the final battle against the Demon Lord! ...Or at least, it-s supposed to be, but Seiya suddenly goes missing while the rest of the party is taking a short breather in the imperial capital before the moment of truth?!?! They-ll have to track him down-and when Ishtar reveals the secret of Seiya-s past, his uncharacteristic rashness starts to make a lot more sense...