Chapter 116 of the Jigokuraku manga.
Summary[]
Earlier before arriving at the floodgates, Shugen senses a strange energy emitting from the gourd containing the Elixir of Life and becomes suspicious of its contents, prompting him to taste test it for any underlying poisons before the time had come to hand it over to his superiors, much to the shock of the shinobi accompany him. He then declares it to be safe for consumption. By the time he faces Gantetsusai, the full effects of the elixir is shown to have run its course as Shugen's eyes start to change, along with his heart beating fast. Shugen then starts to fight Gantetsusai. Gantetsusai notices that Shugen is able to fight properly again and that the way he moves his body is similar to Fuchi's, which complicated matters for the swordsman. After his robe is cut, Gantetsusai sees the bandages Fuchi used to heal him with before his death and decides to stop fighting, which made Shugen question if he was ready to surrender. Gantetsusai tells Shugen that he remembered the reason as to why he boarded the ship but that it was not to fight him. He then lets him in on how he came to be known as the "Blade Dragon", explaining that in the past he used to go around the provinces searching for monsters to defeat and that the first one he came across and cut down was a ship's "keel" (竜骨 ryūkotsu?). With that said, Gantetsusai smiles as he brings his sword down and slashes the ship, which resulted in his wounds opening up. He laughs that he was unable to completely cut the ship in half but figures that another attempt would be able to. An angry Rien then steps out and tells Gantetsusai that he could not stop the ship since it is made out of Tao. Gantetsusai says that he has done all he could to slow her down, as the survivors ship pulls up next to Rien's, and readies himself to get off the ship instead of continuing to fight, stating that his life was a gift given to him and that he will not throw it away. However, Gantetsusai tells Rien and Shugen that someone else stronger than him will arrive shortly and that he hopes their ready to face him. He then becomes happy to see that Gabimaru has made it just in time. Gabimaru jumps onboard the ship, compliments Gantetsusai for the work he has done, and tells him that he will handle the task of taking down the ship as he faces both Rien and Shugen.