Feeling ill-prepared for the looming battle against Mash the Dragon King, Seiya returns to the underworld to acquire some new skills. But every boon gained from this dark realm comes at a cost. While Seiya practices a stealth ability, Rista turns invisible! As he hones the power of darkness, disaster strikes! Will Seiya be able to master these new techniques before the drawbacks wipe out his party?!
Story by Light Tuchihi and art by Saori Toyota.