Hunter x Hunter Episode 31: Destiny x and x Tenacity

One month after Gon's arm was broken, Killua enters Gon's room to find him easily walking on his hands, completely healed. Killua expresses surprise at Gon's quick recovery, noting it should have taken longer. Killua then reveals he has tickets to an upcoming fight featuring Hisoka. He shares that Hisoka's record is 8-3 with 6 KOs, all death KOs, and his only losses were due to no-shows, meaning he has never truly lost in the arena. Hisoka has only given up 4 points in his 8 fights, which Killua states is Floor Master material. Gon becomes excited at the prospect of seeing Hisoka fight. Hisoka's opponent is Kastro, the person who previously scored points against Hisoka. Killua hopes Gon can learn strategies from the match, but Gon remembers his promise to Wing not to train in Nen for two months.

Killua assures Gon it will be fine, but Wing and Zushi suddenly appear. Wing strictly forbids Gon from watching the match, stating that despite his healing, the two-month mandate still stands, and he must wait another month. Wing instructs Gon to practice Ten in the meantime. Killua decides to go to the match alone. Later, Gon watches a TV announcement for Hisoka's match but turns it off, looking at a thread Wing tied on his finger, recalling his promise. The announcer, Cocco, mentions that Kastro, who lost to Hisoka two years prior, is seeking revenge and has a 9-1 record, one win away from becoming a Floor Master.

Killua decides to observe Kastro by sneaking into his room. He bypasses an employee and notices Kastro's door slightly ajar. As he approaches, he sees Kastro on a couch and activates Zetsu before peering inside. Kastro, from behind Killua, asks what he is doing. Killua turns to find the couch empty, bewildered by Kastro's sudden appearance. Killua playfully asks for an autograph, but Kastro already knows who he is and that he is friends with Gon. Kastro commends Killua's Zetsu but says he activated it too late. Killua asks how Kastro managed to sneak up on him, but Kastro keeps it a secret, suggesting they might fight someday.

Hisoka and Kastro enter the ring. Kastro thanks Hisoka for motivating him to become stronger, stating all his previous matches were just practice. As the referee starts the match, Kastro charges and swings at Hisoka's head. Hisoka dodges, but still receives a sharp punch to the face, surprising him. Killua, watching, is amazed by the attack. Hisoka smiles and laughs. Kastro attacks again, and Hisoka sees his left hand charging. Hisoka dodges, but a strong swipe hits the left side of his face. The audience falls silent. Kastro continues his attack, and Hisoka pulls back. Hisoka blocks a kick, but Kastro appears behind him and hits him, knocking him down. The score becomes 4-0 in Kastro's favor. Wing and Zushi observe the match, with Wing appearing to understand the situation.

The referee asks Hisoka if he can continue. Hisoka smiles again, trying to understand how Kastro keeps disappearing. Kastro begins to charge his special attack, "Tiger Bite Fist," exciting the crowd. Hisoka mockingly offers his left arm, but Kastro takes his right arm instead. The crowd screams as Hisoka's arm flies through the air. Hisoka claims this is part of a plan, then dodges another attack from Kastro and catches his own severed arm. Hisoka deduces that Kastro's Nen ability involves creating a double, which Kastro confirms. Kastro then creates a perfect double next to himself. Wing explains that this doppelganger draws energy from the original, and despite Kastro's appearance, he is using an enormous amount of Nen to create it. Hisoka explains Kastro's power is more effective when he creates the double, then makes it disappear so the original can attack. Kastro charges his ultimate special ability, "True Tiger Bite Fist." Hisoka licks his lips, excited by the challenge.