InuYasha the Movie 3: Swords of an Honorable Ruler

Was the Third InuYasha Movie. It was about a third sword with the ability to resurrect the dead.

Plot
On a snowy day near the ocean, blood drips from the left hand of a silver haired demon. Another demon, Sesshomaru, asks his father if he insists on going and asks for his two swords, Tessaiga and Sounga. But his father asks if he desires power so much, he must have someone to protect; Sesshomaru says no, as he has no need for such. His father then transforms into his true dog form, running off. Myoga, clinging near his right eye, pleads his master to reconsider, for his wounds from his battle with Ryukotsusei have not yet healed but the Dog General refuses, as he must reach his human lover, Izayoi, which is just giving birth to his second son, and that he doesn't believe he is longed for this world.

At a mansion, guarded by many samurai, their leader, Takemaru of Setsuna, ignoring the midwife's warnings, enters the birthing chamber as a lunar eclipse begins. He tells Izayoi, that he had always loved her but loaths the fact that her heart has been stolen by a demon and strikes her. As he leaves, he hears the cries of a newborn half-demon. At that moment, the Dog General arrives at the door, using his Wind Scar to cut through the lines, despite being hit by a few arrows. After hearing that Takemaru slew Izayoi, he slices off the samurai's left arm and enters the mansion, just as Takemaru's men set a flame. Inside, the General finds Izayoi and uses Tenseiga to revive her. He then covers his love with the Robe of the Fire Rat. Takemaru then approaches, determined to fight to the death. The General draws his third sword, Sounga and tells Izayoi that their son shall be named InuYasha and battles Takemaru as the mansion collapses on them. Izayoi, holding her infant son, escapes.

In the present, Sounga is found to be a national treasure of Kagome's family. 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. Sounga's sheave, Saiya, says that InuYasha must master the sword before it destroys the modern world. But instead, it takes possession of his arm but InuYasha manages to convince it to return to the past.

Emerging from the Bone Eater's Well, Sougna causes InuYasha to revert to his demonic nature and attacks a nearby village. Miroku and Sango stop him from hurting anyone as the village evacuates. InuYasha unleashes the sword's Dragon Twister, which is more deadly than the Backlash Wave, wrecking a huge amount of destruction which they avoid. InuYasha rest when the sword is out of energy.

Kagome returns to the past with Saiya, who apparently knows Myoga.

Sounga brings InuYasha to the territory of ogre demons, and slays three. Kagome and company later come upon them but the corpses awaken as walking dead. Slashed, some parts still move and they are filled with miasma, which Miroku finds out when he sucked one in. Saiya advises they use fire but Shippo's is too weak so Kagome purifies them. Only one orge leaves the skirmish.

InuYasha meets up with Sesshomaru, who is disgusted that the Sounga came into his possession. As the brothers do battle, whenever their blades clash, Sounga knows Sesshomaru'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 would've not have met a miserable fate. Sesshomaru grab Tessaiga and uses the Wind Scar in an attempt to silence the sword, severely burning his hand. But InuYasha and Sounga survive and the sword is desperate for more blood and attacks Rin and Jaken.

Kagome meets up with Totosai, who also knows Saiya. He explains that Sounga 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 Sesshomaru tries using his poison claw. Sounga flies away and the enchanted beads scatter. InuYasha then goes off on his own to destroy the sword.

The undead ogre demon finds Sounga and attempts to pick it up but instead becomes its host. It went into the netherworld and retrieved Sesshomaru's left arm before coming to the gravesite of Takemaru. Calling out to Takemaru's forgotten soul, it promises revenge against the Dog General by killing his sons. 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 Sounga's spirit represented as a purple smoke.

Elsewhere, Kagome's group had met up with Rin and Jaken, who had been abandoned by Sesshomaru. The old demons decide to tell the whole story concerning Sounga. After InuYasha's father died, they were to under take instructions according to his will; Myoga placed the Tetsuseiga in the master's remains and hid it in the black pearl; Totosai made sure that Tenseiga was passed to Sesshomaru; however, Saiya said there were no instructions for Sounga. They couldn't give it to Sesshomaru for he would kill them for giving him the previous sword and not to InuYasha for he is a little infant. Saiya then proposes 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 Sounga is for both InuYasha and Sesshomaru to join forces but many serious doubt that that will ever happen.

Both the brothers arrive at Takemaru's gravesite and Sesshomaru decides since InuYasha is unaware of the human's connection to Izayoi, he will die ignorant. The two draw swords against each other; InuYasha tells his brother that Tetsuseiga's barrier rejects him, he can't even pick it up; Sesshomaru would prefer to pleasure in killing the half-breed whose father's blood flows in his veins; InuYasha protested that he will destroy Sounga; Sesshomaru says he doesn't even know what their father looked like. InuYasha uses the Backlash Wave against Sesshomaru but he repels it with his Dragon Strike. But Tetsuseiga's sheath protects him.

Takemaru slays entire armies and an entire castle. Using Sounga, he resurrects at least two thousand soldiers, making them his army of the undead. Kagome's group faces them in a titanic battle; InuYasha and Sesshomaru also join. Takemaru has one of the undead grab the Tenseiga, attempting to destroy it with gunpowder but it instead flies off. Rin finds it but the undead ogre demon grabs her and Kagome and takes them to Takemaru; Sesshomaru and InuYasha follow suit. Sounga tells Takemaru that the girls are no different then Izayoi and the samurai proceeds to kill them, for those who consort with demons are all Izayoi in his eyes. Kagome is partially protected by Sounga's sheath and Rin is confident that Sesshomaru 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. He sucks in all of the dead.

Kagome tries throwing one of the beads at the headless ogre body but misses; InuYasha slices it in half. Kagome nad Saiya tell InuYasha to join forces with Sesshomaru to overcome Sounga's Dragon Twister but he refuses and runs off. Sesshomaru fails in using Tenseiga to slay Takemaru, who is just resurrected by Sounga. InuYasha 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 Sounga 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, 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. Sesshomaru then slashes at the imps trying to resurrect him. But Sounga 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. Saiya puts up a barrier to protect the nearby humans from being overcomed by the dead souls from the netherworld, calling out to the living. InuYasha and Sesshomaru battle with Sounga, each wanting to defeat the evil sword themselves. Kagome tells them to work together but they don't listen so she tries to purify Sounga 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. Sounga believes that he finished off the half-demon and turns to Sesshomaru but InuYasha gets up and uses the Backlash Wave again. Sesshomaru remembers when his father asked if he had someone to protect and short flashbacks of Jaken and Rin. But she stoutly claims he has no one to protect and combines his Dragon Strike with the Backlash Wave, overcoming the Dragon twister and destroying Sounga's body, casting the sword into the netherworld. Inu no taishou then appears, saying he proud of them for sealing Sounga forever as the portal closes. Saiya says that the master wanted his son to work together but they find that ridiculous. The other old demons ask Saiya why he didn't speak up sooner; he claims he was just thinking of what's best for the brothers; he really forgot.

In the post-credits, Kagome tricks InuYasha into putting back on the enchanted beads.

Plot is incomplete