Sō'unga

Sounga is a fictional sword in the anime and manga series InuYasha. It is the opposite of Sesshomaru's inherited sword, Tenseiga, "the sword of life or heaven", and InuYasha's inherited sword Tessaiga, "the sword of death or earth".

Sounga, "the sword of hell or of world conquest", can summon 100 dead souls in one swing. In the third movie of InuYasha, the combined powers of the Tessaiga and the Tenseiga succeeded in defeating Sounga, which was stronger than either of them alone.

Sounga, unlike the Tessaiga or Tenseiga, was not created by Totosai from InuYasha's father's fang and it is unknown how InuYasha's father came to own it. Also, unlike the other two, Sounga has a mind of its own. When held by a human, Sounga takes control of them, and they will kill everything they possibly can, but when held by a yōkai, then Sounga will try to persuade them to do its bidding. But InuYasha's father never let Sounga control him. Saying it was an act of weakness if he let what he should be controlling take control of him.

When InuYasha grasped Sounga, he was taken over, but regained control for a short period of time.

Special attacks and/or abillities

 * Dragon Twister: Sounga most powerful attack, and more powerful than Tessaiga's Backlash Wave, Sounga summons a large, violent, and powerful tornado that destroys, or kills evreything in its path.
 * Sheath of Sounga: Kept Sounga dormint for what seemed like 1000 years. Advised Myoga and Totosai to throw him with Sounga sheathed into The Bone-eaters Well.
 * Bringing back the Dead: When Sounga is in control of a "Lesser" yōkai, he can bring back a corps from the dead, and control it, or give it free will.