Ryūkotsusei

"My body is mightier than iron!"

- Ryūkotsusei

was an extremely powerful dragon daiyōkai who terrorized the Plains of Musashi until he was confronted by the Inu no Taishō and sealed to a cliff face in the Valley of Ryūkotsusei. The wounds that Ryūkotsusei inflicted on the Inu no Taishō ultimately led to the latter's death.

Many years later, Ryūkotsusei was reawakened and brought out of dormancy by the hanyō Naraku. Ryūkotsusei had no intention of exacting revenge on Inuyasha, the younger son of the Inu no Taishō, to suit Naraku's purposes, but after destroying Naraku's demon puppet, Ryūkotsusei decided to fight the son of his old enemy to entertain himself. After a very arduous battle, during which Ryūkotsusei was injured many times but never succumbed, Inuyasha defeated the dragon with the Bakuryūha and in defeating Ryūkotsusei, took a major step in the training of his sword, the Tessaiga.

Sealed by the Inu no Taishō
200 years before the shattering of the Shikon no Tama, Ryūkotsusei was a feared daiyōkai and created mayhem across the land. The Inu no Taishō, a powerful dog demon who defended Japan against threats such as Ryūkotsusei, confronted the dragon and engaged him in battle, in order to put an end to his rampage. Ryūkotsusei was a truly terrible foe, however, and not even the Inu no Taishō could defeat him or put him under seal so easily. The Great Dog Demon had faced many powerful demons in the past and had stopped several invasions by powerful daiyōkai and their armies, but Ryūkotsusei was so singularly powerful that the Inu no Taishō was fatally wounded before finally using one of his claws to pierce Ryūkotsusei's thick skin directly above the heart, thus sealing his powers into a state of dormancy.

Revival
50 years later, Ryūkotsusei was visited by the Inu no Taishō's youngest son, Inuyasha, who was on a mission to strengthen his sword, the Tessaiga, by driving it into Ryūkotsusei's heart and killing him. However, Inuyasha's enemy, Naraku, desired to revive Ryūkotsusei, hoping the powerful demon would be able to destroy his hated foe. Naraku used his miasma to disintegrate the claw of the Inu no Taishō that kept Ryūkotsusei under seal. Once done, Ryūkotsusei's powers returned and his heart began to beat once more. As he began to stir, a menacing aura began to collect around him, darkening the skies and summoning storm clouds. As Ryūkotsusei broke free of the cliff he had been sealed to, Naraku called out to him, telling him that Inuyasha was the son of the one who hurled him into dormancy, encouraging him to take avenge himself by destroying Inuyasha.

While the flea Myōga attempted to persuade Inuyasha to flee, Inuyasha expressed his preference for a direct confrontation, since he believed that simply killing Ryūkotsusei while he was dormant to be too cowardly. Ryūkotsusei heard this and asked Inuyasha if he seriously thought that he could defeat him, expressing his amusement at such a notion. Ryūkotsusei lunged forward, crushing the hill Inuyasha had been standing on, proceeding to then fire an energy blast in Inuyasha's direction. While the hanyō dodged the blast, it soon became apparent that Ryūkotsusei's true target was not Inuyasha, but Naraku, who was obliterated. Ryūkotsusei wanted to kill Naraku because he believed him to be an eye-sore. However, after destroying him, Ryūkotsusei recognized that what he had hit was just a demon puppet and not the real Naraku, complaining that such a thing hardly constituted a warm-up.

Ryūkotsusei then turned his attention to Inuyasha, expressing his hope that Inuyasha could provide him with more amusement that the demon puppet had. Inuyasha replied that he was more than happy to oblige and attempted to cut Ryūkotsusei by stabbing into the scar left by his father's claw. However, the attack was futile, and Inuyasha was repulsed. Ryūkotsusei taunted Inuyasha, telling him that it was no use since his body was mightier than any armor. He then stated that it was his turn and fired an energy blast at Inuyasha, who barely managed to dodge it in time.

Myōga yet again attempted to persuade Inuyasha to flee, adding that it was his father's battle with Ryūkotsusei and the wounds he was given that ultimately killed him, shocking Inuyasha. Ryūkotsusei was pleased to hear that his old enemy had perished and asked if Inuyasha had come to avenge his father with a ridiculous sword such as the Tessaiga. Inuyasha said he never even met his father, so avenging him was the last thing on his mind. While Myōga scolded Inuyasha for being a "traitorous" son, Ryūkotsusei took advantage of their arguing to slam his tail against Inuyasha, knocking him into a nearby cliff.

Inuyasha charged at Ryūkotsusei, but was met with a continuous barrage of energy blasts which leveled the surrounding landscape. Ryūkotsusei berated Inuyasha for being so weak, claiming that their battle had become more tedious than he expected and that destroying him relieved him of none of the anger he felt towards Inuyasha's father. Inuyasha leapt to attack again, but Ryūkotsusei slammed Inuyasha into a cliff with his claws, telling him again that he would not be able to defeat him with an inferior sword like the Tessaiga. Ryūkotsusei pressed harder into the rock face, demolishing it and leaving Inuyasha to fall into a deep ravine. After Inuyasha dropped the Tessaiga and plummeted to the bottom of the ravine, Ryūkotsusei fired off yet another energy blast, that left Inuyasha badly injured.

However, as Ryūkotsusei closed in, Inuyasha's aura began to change, as his demon blood took over his body without the protection of the Tessaiga. This transformation confused Ryūkotsusei at first, but he realized that Inuyasha's demon blood had awakened and accepted it, since it would prove more of a challenge. In this state, Inuyasha was much stronger and even capable of piercing Ryūkotsusei's skin, causing him minor injury. Ryūkotsusei told Inuyasha not to get ahead of himself and fired an energy blast, leaving only a crater behind. Ryūkotsusei soon realized that he had missed and was unable to dodge Inuyasha's next attack, which sent him crashing into a cliff. This was Inuyasha's original intent, as he wanted to retrieve the Tessaiga from under Ryūkotsusei, who had slithered over top of it. As Inuyasha went to claim it, Ryūkotsusei became angry at Inuyasha's arrogance at thinking that he could defeat him, and fired an energy blast at him, however, Inuyasha was saved by the barrier of the Tessaiga's sheath. Ryūkotsusei declared angrily that Inuyasha would not be able to stop his blast a second time, which according to Tōtōsai was the truth. However, Inuyasha was saved yet again, this time by the monk Miroku using his Kazaana to alter the course of Ryūkotsusei's blast slightly.

Demise
Inuyasha finally reclaimed his sword, reversing his transformation. Ryūkotsusei told Inuyasha that he was very weak, pointing out that he couldn't even hold up his sword. Inuyasha replied that he had his reasons for needing the Tessaiga to defeat him. Ryūkotsusei laughed at him and told him that this time he wouldn't hold back. As he attacked Inuyasha once again, Inuyasha dodged the blast and stabbed his sword into Ryūkotsusei's heart, the Tessaiga having become lighter for him after his declaration. Although it caused him a great deal of pain, Ryūkotsusei was not affected in any way, and indignantly told Inuyasha that he would pay for wielding his sword against him. Ryūkotsusei's resiliency surprised even Inuyasha and his friends, as he proceeded to fire a string of energy blasts at Inuyasha. The hanyō attempted to strike back, but was slammed into a cliff once again by Ryūkotsusei's tail. Ryūkotsusei laughed at Inuyasha, telling him that he had warned him that his sword was useless.



Ryūkotsusei fired another energy blast at Inuyasha, but it was overcome by the Kaze no Kizu, which plummeted into Ryūkotsusei and sent him reeling back. Although Inuyasha realized he could now invoke the Wind Scar at will, Ryūkotsusei quickly recovered and as he rose, asked Inuyasha if that was the best he could do. Inuyasha was unnerved that not even the Wind Scar phased Ryūkotsusei. The dragon proclaimed that play time was over, and that this time he would destroy Inuyasha, as he amassed an immense demonic aura and fired one last, colossal energy blast. Inuyasha couldn't avoid it since it was so gigantic, so he decided to cut through it with the Wind Scar, creating the Bakuryūha, which successfully took control of Ryūkotsusei's demonic energy and reversed the flow back towards him. Ryūkotsusei watched in horror as whirlpools of his own demonic energy sliced his body to pieces. Ryūkotsusei's head was destroyed, and he lamented the destruction of his invincible, rock-hard body before his face was finally obliterated by the Backlash Wave. The remaining pieces of his body crumbled to dust and were blown away with the wind.

Appearance
Ryūkotsusei has the appearance of a typical dragon but with a mask on his head. This mask is Ryūkotsusei's real face as it does the talking and directs the body while the dragon's mouth shoots out powerful energy blasts. Both the mask and the dragon have red eyes. Its long body is covered in thick armored hide which is near impenetrable as Inuyasha quickly realizes. He has two fairly short arms, despite this, he was able to slam Inuyasha up against the cliffside without struggle. Along with his large intimidating body, his demonic aura can easily disintegrate rocks without even having the dragon come in contact with it. Unlike other powerful demons, Ryūkotsusei does not appear to have a humanoid appearance.

Abilities

 * Enhanced Strength: Ryūkotsusei was able to dominate over Inuyasha for the first half of the battle, only to momentarily overwhelmed by his demonic transformation. His full power was not shown in the series, but it was enough for one of the strongest characters in the series, the Inu no Taishō, to be unable to defeat him and had to seal him away, and is the ultimate reason for his death; suggesting he was very formidable.


 * Enhanced Defense: Ryūkotsusei has an incredible armored hide that is nearly impenetrable, even striking the scar Inu no Taishō's claw left in it had no effect. However, when Inuyasha transformed into his full demon form, he was able to inflict wounds on Ryūkotsusei with his claws alone. After Inuyasha repossessed Tessaiga, he was able to stab Ryūkotsusei in the heart and use the Kaze no Kizu on him; however, this attacks only managed to stun Ryukotsusei.


 * Thunder Attack Bullet: These large, powerful, pure white energy spheres are launched out of Ryūkotsusei's mouth and can be fired numerous times consecutively. In the anime, it was so powerful that when Miroku used his Kazaana on one of these blasts, he was only able to change its course slightly. Tessaiga's sheathe was able to protect Inuyasha from one of these attacks.

Trivia

 * Ryūkotsusei appears in the second ending; Fukai Mori. Though, his appearance is somewhat different when compared to his actual debut in the anime.


 * The events of the Inu no Taishō's battle with Ryūkotsusei are further explained in Swords of an Honorable Ruler. The film states that directly after the battle between Ryūkotsusei and the Inu no Taishō, the Inu no Taishō was forced into saving Inuyasha and his mother before he had recovered from the injuries inflicted by Ryūkotsusei, thus contributing to his death.