Episode 18

Tacticians' Showdown (軍神闘衣) is the eighteenth episode of the Orient anime series.

Summary
Musashi and the rest, decide to follow Kanetatsu after he asks for Musashi's and the Obsidian Goddess help. On their way, Kojiro mentions that they got involved with the Uesugi to learn more about his father, but as their lives are at stake, if Musashi and Tsugumi wish, they can leave. Kanetatsu sees that Tsugumi is carrying something and guesses its Musashi's Kitetsu Blade, as he heard they stole it from the execution grounds. Musashi wonders why they did it, and Kojiro and Tsugumi explains they planned on saving him, since he is their friend. Kanetatsu notes that they are great friends and he wishes to save his friends too, but to do so, he needs to defeat a Kishin and the Bushi with it. Recalling he wants to save Michiru, Musashi tells Kojiro he has reasons to continue and its not just about his father anymore. The group then reach the Uesugi Bushi's mausoleum.

In the times before humanity had the means to fight the oni, an enigmatic woman delivered the first Kitetsu Blade unto the world. She had dominion over all blade energy, the Obsidian Goddess. Even after her passing, her soul persisted. Kanetatsu explains that whoever her spirit inhabits, is said to have her power sleeping within their body. Kanetatsu then brings a chest, stating its a treasure said to unlock the goddess' power. Musashi wonders if with this treasure, if he will be able to fight the black dogs, and Kanetatsu believes so. He explains that they are calling themselves the Obsidian Eight, they wield Kitetsu Blade, but side with the oni, and have been killing Bushi for over a century. Musashi accepts, as he wish to become stronger in order to be able to protect Kanemaki Bushi in the future. Kanetatsu then opens the chest and brings out a chalice containing the blood of the Goddess, who is said to have died hundred years ago. Learning he needs to drink the blood, Musashi changes his mind as he finds it nasty. Annoyed, Kanetatsu forces him to drink it. However, after drinking it, Musashi doesn't feel anything had changed at all. As they leave the mausoleum, Musashi feels something moved, but guesses its his imagination, in reality, hundreds of Kitetsu Blade that were in the mausoleum had started floating and pointing at him.

Kuroko Usami forms a plan, to defeat Yamata no Orochi, save Tatsuomi Uesugi and defeat the Obsidian Eight at the same time. The first mission is given to the Uesugi's white-clad first deployment who has to slay 10,000 carved-mouth oni. The second deployment, Takeda reinforcements, have the duty of breaking Orochi's horns in place of the black-clad Uesugi soldiers. The third deployment, are Uesugi soldiers, who will remain at the castle due to their blocked blade energy. They have three days to do so, otherwise Orochi will fed back the minerals it consumed to the Black Kishin and the Black Kishin will split Hinomoto. Seiroku, Shiro and Yataro have a spy present at the strategy meeting and hear the whole plan. Seiroku notes that they just need to defend Orochi for three days and they win.

Musashi joins his squad and is glad to see them. They inform him that the four Saruwatari fighters are gone and the Shimazu were ordered to stay. Musashi reveals he knows everyone names and that he didn't knew how important is for Bushi to fight together. As Bushi can't fight alone, he wants to know more about everyone. Kuroko then approaches them and states she has a task for them all. Meanwhile, Kojiro recalls asking Kanetatsu about his father, but he didn't knew anything. Kanetatsu suggested that Tatsuomi should know, since his signature is on the document.

Naotora disagrees with Kuroko's plan, stating they are weakened and need to focus only on rescuing their leader and not slaying the Kishin. But if they insist, then Takeda Bushi won't be joining them. Hearing that, Yataro and the rest think their job will be easier. Shiro expresses desire to fight Naotora, while Seiroku is focused on Kanetatsu. Yataro states he will be capturing the goddess, but Seiroku tells him they will do that and as the rest of the Eight, decided to relieve him from his job. Seiroku tells him that its not his fault that he is weak.

The battle starts next day. Orochi targets anyone who threatens him or its offspring. Using that, Kuroko leaves some ships to be destroyed to spill oil and burns them, causing Orochi to start attacking its shore and close range. As that creates smoke, Musashi's group is able to swim undetected around the oni. Getting on the island, their job is to destroy Yura mine and stop Orochi's food supply. However, as Seiroku had listened to Kuroko's plan when she told it to Musashi, he prepared an oni which Musashi's group now faces. However, the Shimazu then join Musashi and easily destroy the oni. Yataro learns that the oni is destroyed, but also that Takeda forces had join the battle. Naotora had followed Kuroko's plan and acted like he won't be joining them as Kuroko knew there were more spies. Yataro quickly calls Seiroku, who had went to put out the fires. Kuroko reveals that she planned to destroy the mine and restore their blade energy chain, which requires neutralizing Seiroku. Musashi's group prepares to blow up the mine, but Shiro appears and transports the bombs over Takeda's Bushi. Seiroku had been expecting this and now orders Shiro to kill the goddess.

Seiroku uses his spy and contacts Kuroko, to laugh about his win and states he loves when his plans are fulfilled. However, Kuroko tells him she isn't done. Yataro tells Seiroku that Takeda Bushi are fine. Seiroku is surprised and Kuroko tells him its because his spies relayed faulty information. Seiroku doubts it, otherwise Kuroko knows all of his spies. Kuroko explains that she knew the moment his men didn't hesitate to walk over Uesugi's clan crest flag. Seiroku can't believe he was tricked to be where they want, but doesn't believe Uesugi had left anyone who can challenge him. Kanetatsu then comes and attack Seiroku, with Kuroko stating they just need to shatter his Kitetsu Blade to undo the energy blocking.