Byaku and Matsudo

Byaku and Matsudo (因縁の決着, Innen no Ketchaku) is the 47th episode of the Kekkaishi anime adapted by Sunrise.

Summary
Byaku runs through Kokuboro's castle, with Heisuke Matsudo and Kagami chasing him. After cornering him, Heisuke addresses Byaku as Shiranuma, and comments on how young he looks, despite being nine years older than Heisuke himself. Byaku disapproves of Kagami taking the appearance of his late wife, and Heisuke is equally angry that Byaku never once gave any sign that he loved her, and supposedly experimented on her. Heisuke admits to having dug up both of their graves, but finding Byaku's empty, he'd assumed they had run off together. Upon finding Risa's body in her grave, Heisuke did everything he could think of to revive her. Though his methods failed, in the process he managed to summon a demon that offered to make a contract with him.

Byaku summons a multitude of demon bugs, reveals that there is a nest beneath them, and gives Heisuke a chance to leave unharmed. He also states that Risa's death was an accident, but Heisuke insists that Byaku killed her so he could gain a new body. Byaku orders his bugs to attack, and they swarm Heisuke and Kagami, but Kagami kills them all. Heisuke says that Byaku will never find what he seeks because he is empty inside, and is amazed that Risa could ever fall in love with him. Byaku replies that Risa was only using him because he did whatever she wanted. After they were married, she craved immortality, so Byaku performed numerous experiments to grant her wish. One of these left her horribly disfigured, and after instructing Byaku to burn down their home, Risa stabbed herself. Heisuke refuses to believe him, and Byaku says it doesn't matter since it happened 50 years ago. Heisuke reveals that Risa was insecure, because she feared she only had beauty to offer and that her husband would leave her, and this was why she wanted to stay young and beautiful.

Byaku's bugs eat through the floor, dropping Heisuke and Kagami into their nest. Kagami devours the entire nest and carries Heisuke out, able to track Byaku by scent. Suddenly, Byaku's worms emerge from the floor and splash a strange liquid onto Heisuke. Byaku appears and challenges Heisuke, who accepts. This triggers Byaku's ability, which opens up large holes in Heisuke's body where the liquid touched him, effectively paralyzing him. Byaku intends to insert worms through the holes so he can control Heisuke. Heisuke accuses Kagami of allowing this to happen on purpose, and it is only as Byaku's worms and bugs are closing in that Kagami finally acts, destroying them and stabbing Byaku through the chest. Kagami explains that it took a while to find Byaku's core, and assures Heisuke that while Byaku won't die from the wound, the bugs will eat him eventually. Kagami also reveals that Byaku's core is still human. Heisuke demands to know if Byaku ever loved Risa, and when he says no, Heisuke angrily drives his cane into Byaku's mechanical eye. Heisuke is disappointed because he promised Risa he would take care of Byaku and was unable to save his soul, but Kagami comforts him and they leave Byaku to his fate.

Trivia

 * This is the episode in which Yoshimori and Tokine do not appear.