InuYasha the Movie 3: Swords of an Honorable Ruler

is the third InuYasha movie. It was released on December 20, 2003 in Japan (between episodes 136 and 137) and in the United States on September 6, 2005.

Plot
On a snowy night near the ocean, blood drips from the left hand of the Inu no Taishō. His son and heir, Sesshōmaru, asks his father if he insists on going and asks for his two swords, Tessaiga and Sō'unga. But his father asks if he desires power so much, he must have someone to protect; Sesshōmaru says no, as he has no need for such. His father then transforms into his true dog form, running off.

At a mansion, guarded by many samurai, their leader, Takemaru of Setsuna, coming to the birthing chamber ignores the midwife's warnings and takes his spear, killing the midwife. At the birthing chamber, Izayoi who is just giving birth to his second son whose calling "my dearest" to Inu no Taishō. While Tōga is on his way to the mansion, Myōga, clinging near his right eye, pleads his master to reconsider, for his wounds from his battle with Ryūkotsusei have not yet healed, but the Inu no Taishō refuses, as he cannot afford to lose his human wife, and that he doesn't believe he is long for this world.

Back at mansion, Takemaru approached the birthing chamber as he observed the night of the lunar eclipse begins. He tells Izayoi, that he had always loved her but loathes the fact that her heart has been stolen by a demon and stabs her with a spear. As he leaves, he tells her that his feelings for her will never change, and she reaches out to the window while observing the lunar eclipse and Inu no Taishō on the cliff observe the mansion telling her that he's coming for her. As the moon darkens, a half demon was born and when Takemaru coming back to the gate, he hears the cries of a newborn half demon.

At that moment, the Inu no Taishō arrives at the gate, using his Kaze no Kizu to cut through the lines, despite being hit by a few arrows. As Takemaru tells Inu no Taishō a little late, causes him to surprise and hearing that he slew Izayoi, he slices off the samurai's left arm and enters the mansion, just as Takemaru summons his men to set it aflame with Inu no Taishō and the rest inside. Inside, the Inu no Taishō finds Izayoi and uses Tenseiga to revive her, and covers her with the Robe of the Fire Rat to protect her from the fire. Takemaru then approaches, as Inu no Taishō draws his third sword, Sō’unga and Takemaru determined to fight to the death tells him to let them journey together into the netherworld. Inu no Taishō tells Izayoi to live long and give his second son's name Inuyasha, Takemaru asks him what's Inu no Taishō talking about, he answered "the infant's name" as their son shall be called Inuyasha, Izayoi agreed, calls Inuyasha as Inu no Taishō tells her to get out and she leaves. Inu no Taishō produce the Dragon Twister to battles Takemaru as the mansion collapses on them. Izayoi, holding her infant son, escapes as Inu no Taishō's voice tells her that she must survive, live a long life, live long and well with Inuyasha.

In the present at Kagome's school, Kagome and her friends playing volleyball, but then Inuyasha, who had followed Kagome to the present to make sure that no harm comes to her as she realized that Inuyasha came. At Higurashi storehouse, Sō’unga is found to be a secret treasure of Kagome's family. On their way to Kagome's home she asked Inuyasha why did he come to her school, he answered that he didn't want anything happen to her, but she assures him in the future there are no demons. She tells him that she's playing volleyball, which reminds Inuyasha as a Kemari ball game, so he remembers as the others don't let him to play and walked away after one of them threw. As he approached to his mother, he first saw his mother's tears Suddenly, the sword flies off to find the nearest demon, finding Inuyasha, who had followed Kagome to the present to make sure that no harm comes to her but she assures him in the future there are no demons. Sō’unga's sheath, Saya, says that Inuyasha must master the sword before it destroys the modern world. But instead, it takes possession of his arm and Inuyasha manages to convince it to return to the past.

Emerging from The Bone-Eater's Well, Sō’unga causes Inuyasha to revert to his demonic nature and attack a nearby village. Miroku and Sango stop him from hurting anyone as the villagers evacuate themselves. Inuyasha unleashes the sword's Dragon Twister, which is more deadly than the Backlash Wave, wreaking a huge amount of destruction, though Miroku and Sango avoid this on Kirara. Inuyasha then wanders off to rest whilst the sword is out of energy. In the meantime, Kagome returns to the past with Saya, who apparently knows Myōga.

Sō’unga brings Inuyasha to the territory of ogre demons, and slays three. Kagome and company later come upon them but the corpses awaken as the walking dead. Slashed, some parts still move and they are filled with miasma, which Miroku finds out when he sucks one in with his Wind Tunnel. Saya advises they use fire but Shippō's is too weak so Kagome purifies them. Only one orge leaves the skirmish.

Inuyasha soon meets up with Sesshōmaru, who is disgusted that the Sō’unga came into his possession. As the brothers do battle, whenever their blades clash, Sō’unga knows Sesshōmaru's every thoughts, especially that Inuyasha cut off his left arm. It evens taunts him, saying that if his father had listened to him, he wouldn't have met a miserable fate. Sesshōmaru grabs Tessaiga and uses the Kaze no Kizu in an attempt to silence the sword, severely burning his hand, but Inuyasha and Sō’unga survive. The sword, now angry, wishes for more blood and prompt Inuyasha to attack Rin and Jaken. but, before he was able to hurt them, Kagome told him to sit.

Kagome meets up with Tōtōsai, who also knows Saya. He explains that Sō’unga is a sword possessed by the spirit of an ancient evil demon. She uses her "sit" command to hold Inuyasha and grabs him, just as Sesshōmaru tries using his poison claw. Sō’unga flies away and the enchanted beads scatter. Leaving an unconscious Kagome behind, a guilty Inuyasha then goes off on his own to destroy the sword.

The undead ogre demon finds Sō’unga and attempts to pick it up but instead becomes its host. It goes into the netherworld and retrieves Sesshōmaru's left arm before coming to the gravesite of Takemaru. Calling out to Takemaru's forgotten soul, it promises revenge against the Inu no Taishō by killing his sons. So Takemaru's eyes glowing red and his skeleton body glows and comes out of his grave as the dirt comes to his skeleton body into the skin.

Elsewhere, Kagome awakens and finds that Rin and Jaken are with them, having been abandoned by Sesshōmaru. The old demons decide to tell the whole story concerning Sō’unga. After Inuyasha's father died, they were to undertake instructions according to his will; Myōga placed the Tessaiga in the master's remains and hid it in the black pearl; Tōtōsai made sure that Tenseiga was passed to Sesshōmaru; however, Saya said there were no instructions for Sō’unga. They couldn't give it to Sesshōmaru for he would kill them for giving him the previous sword, and Inuyasha was only an infant. Saya then proposed to hold the sword quietly for at least seven hundred years and have it thrown into the Bone Eater's Well. Now the only way to defeat Sō’unga is for both Inuyasha and Sesshōmaru to join forces but many seriously doubt that that will ever happen.

Meanwhile, Takemaru is resurrected and given the left arm to use the Dragon Twister. As he grasps the sword, he is given a demonic appearance, with Sō’unga's spirit represented as a purple smoke.

Both the brothers arrive at Takemaru's gravesite and Sesshōmaru decides since Inuyasha is unaware of the human's connection to Izayoi, he will die ignorant causing the two to draw swords against each other. Inuyasha tells his brother that since Tessaiga's barrier rejects him, he can't even pick it up, whilst Sesshōmaru would prefer the pleasure in killing the half-breed whose father's blood flows in his veins. Inuyasha then protested that he would destroy Sō’unga, however Sesshōmaru retorted that he doesn't even know what their father looked like. Inuyasha attempted to use the Backlash Wave against Sesshōmaru but he repelled it with his Dragon Strike. However, Inuyasha was protected by Tessaiga's sheath, prompting Sesshōmaru to leave.

Takemaru slays entire armies and an entire castle and using Sō’unga, he resurrects at least two thousand soldiers, making them his army of the undead. Kagome's group faces them in a titanic battle, with Inuyasha and Sesshōmaru also joining in on their own. Takemaru has one of the undead grab the Tenseiga, attempting to destroy it with gunpowder but it fails and the sword flies off. Rin finds it, but the undead ogre demon grabs her and Kagome and takes them to Takemaru, prompting Sesshōmaru and Inuyasha to follow. Sō’unga tells Takemaru that the girls are no different than Izayoi and the samurai proceeds to try and kill them, for those who consort with demons are all Izayoi in his eyes. Kagome is partially protected by Sō’unga's sheath and Rin is confident that Sesshōmaru will save them, which he does. The girls try to run, but their path is cut off by the ogre. It grabs Kagome, causing the enchanted beads to fall from her pockets. Rin throws one of them at it, disintegrating its head.

Outside, the others tells Inuyasha to rescue Kagome while they hold off the soldiers. But there are so many that many of their fire users got exhausted. Miroku uses his last resort: his Wind Tunnel, despite the danger to his body, sucking in all of the dead and becoming severely weakened.

Kagome tries throwing one of the beads at the headless ogre body but misses, however Inuyasha arrives and slices it in half. Kagome and Saya tell Inuyasha to join forces with Sesshōmaru to overcome Sō’unga's Dragon Twister but he refuses and runs off. Sesshōmaru fails in using Tenseiga to slay Takemaru, who is just resurrected by Sō’unga. Inuyasha then attempts to hit both of them but misses. Takemaru remarks that the half-demon looks like Izayoi and informs him of his part in her death. As they clash blades, Inuyasha is able to push Takemaru back. The latter and Sō’unga are bewildered at what they are seeing, for such power is impossible for a demon; Inuyasha retorts that he's half a demon and his human desire to protect someone is increasing his power and pushes Takemaru through a wall. Takemaru then has an epiphany that when Izayoi wanted him to leave, then he realizes that she was trying to protect him. He murmurs that he'd always loved her as his horn falls off and his flesh erodes, leaving only his skeleton. Sesshōmaru then slashes at the imps trying to resurrect him.

However, Sō’unga isn't finished. It causes the castle to collapse, crushing Takemaru's remains and creates its own body with the arm attached, opening a portal to the netherworld. Once the boundary between both worlds vanish, every living thing will wind up dead. Saya puts up a barrier to protect the nearby humans from being overcome by the dead souls from the netherworld, calling out to the living.

Inuyasha and Sesshōmaru battle with Sō’unga, each wanting to defeat the evil sword themselves. Kagome tells them to work together but they don't listen so she tries to purify Sō’unga but nearly gets killed. Inuyasha gives her his sheath to protect her as he tries to use the Backlash Wave to stop the Dragon Twister but it barely works. Sō’unga believes that he finished off the half-demon and turns to Sesshōmaru but Inuyasha gets up and uses the Backlash Wave again. Sesshōmaru remembers when his father asked if he had someone to protect and has short flashbacks of Rin and Jaken. Despite this, he stoutly claims he has no one to protect and combines his Dragon Strike with the Backlash Wave, overcoming the Dragon Twister and destroying Sō’unga's body, casting the sword into the netherworld.

The Inu no Taishō then appears, saying he's proud of them for sealing Sō’unga forever as the portal closes. Saya says that the master wanted his sons to work together, but they find that ridiculous. The other old demons ask Saya why he didn't speak up sooner; he claims he was just thinking of what's best for the brothers; but the truth is he really forgot.

In the post-credits, Kagome thought that Sesshōmaru don't like humans, and don't know why Rin is with him. Then she tricks Inuyasha into putting back on the enchanted beads as a surprise, which she had managed to put back together thanks to Rin who collected all of its scattered beads, and in a soft tone of voice tells him to sit, as seen the flowers blows as Inuyasha hits the ground, ending the film.

Canonical inconsistencies

 * Much of the film revolves around Inuyasha and Sesshōmaru's feelings concerning their father, particularly their desire to surpass him in strength. However, Inuyasha had already surpassed his father in strength in Season 2 when he defeated Ryūkotsusei, a demon his father hadn't been able to kill while he was alive. Tōtōsai even says as much at the time; however, in the movie, he claims that Tōga is "1000 times stronger" than Inuyasha, which in canon is false, as Inuyasha is stronger, at least with the Tessaiga, although perhaps he is less skilled than his father was. Furthermore, Sesshōmaru is easily able to suppress Inuyasha's Bakuryūha, implying his aura is far stronger than Inuyasha's, and by extension, his father's and Ryūkotsusei's. Yet in the film, he acts as if he will never know if he is stronger than his father because he cannot fight him in person.
 * As in the Panther Devas arc in Season 3, Sesshōmaru struggles with why his father bequeathed the Tessaiga to Inuyasha and the Tenseiga to him. Yet Sesshōmaru already discovered from Bokusenō in Season 2 that Tōga gave Inuyasha the Tessaiga to prevent his demon blood from overpowering his human soul, and Sesshōmaru seems to accept this fact; but in the movie he still seems oblivious to his father's thinking, despite having learned of it two seasons prior.
 * Jaken himself suggests in the Panther Devas arc for Sesshōmaru to join forces with Inuyasha to confront the Panther tribe, yet in the film, when Saya suggests it, Jaken laughs hysterically as if it is impossible, despite the fact that the two brothers have more or less cooperated multiple times in the past, against such foes as the Panther King, the Band of Seven, and Naraku. He also later urges Sesshōmaru not to rely on Inuyasha's help, despite having urged him to do so in previous battles, and despite the fact that Sō'unga was far more dangerous an opponent than the Panther King.
 * In the film, Sesshōmaru falls to his knees in pain after using the Tessaiga, due to its barrier. However, in both the anime and the manga, Sesshōmaru is repeatedly shown touching and even using the Tessaiga without showing any sign of pain or fatigue. Even Jaken shows less outward signs of pain when he touches the sword in Episode 79 than Sesshōmaru does in the movie. In fact, even when impaled, Sesshōmaru shows less outward show of emotion than he does in this film after merely touching the Tessaiga's barrier. Whether Sesshōmaru's out-of-character behavior is a continuity error in the film or done intentionally for dramatic effect is unclear.

Goofs

 * During a total lunar eclipse, when the moon is inside of the umbra, it should've been red due to the refraction of the sunlight by the Earth's atmosphere into the shadow cone, but instead it was pitch black.
 * When Inuyasha was walking through the hole to finish Takemaru of Setsuna, the strap of his kimono was gone.
 * When Rin threw the Beads of Subjugation at the Zombified Oni, the spiritual power they possessed was strong enough to melt its head. However, when the rosary exploded earlier in the film, one of the beads was embedded in Jaken's forehead causing no lasting damage. (On a converse note Rin may be a priestess, either from being revived from Tenseiga or from being born with it Kagome never hit the demon with the beads which might have had the same effect)
 * In a scene during his ascent of the mansion to save Kagome after she was kidnapped by Takemaru, Inuyasha appears to have two Tessaigas: one drawn out in his hand, and the other inside its sheath. This scene is located right before Inuyasha runs into Sesshōmaru, after having just used the Wind Scar.
 * When Kagome yelled the "Sit" command to break Inuyasha out of Sō'unga's spell, Inuyasha should've been face first to the ground. Instead he was on his back when the smoke cleared.
 * Just before Inuyasha defeats Takemaru, we can see Sesshomaru who has three stripes on the left (seen from spectators point of view) side of his face instead of two.

Swords of an Honorable Ruler hu:InuYasha, a film: A világhódítás kardjai 映画犬夜叉：天下覇道の剣 vi:InuYasha the Movie:Swords of an Honorable Ruler 犬夜叉電影：天下霸道之劍