"Hanging with Axel: Part 1", known as "Professor Cobra's Assassin" in the Japanese version, is the one hundred and eighth episode of the Yu-Gi-Oh! GX anime. It first aired in Japan on November 1, 2006, and in the US on May 5, 2007.
Jaden and Jesse Anderson go to investigate something they heard while opening new packs of cards at the Slifer Red dorm. Axel Brodie is training in the forest, hanging upside-down and suspended over a cliff. He recalls his time with his father years ago, who taught him to treat life as being in battle all the time - so that he would be prepared for life and death situations whenever they arise. He sees Jaden and Jesse chasing someone and they confront him, however Jesse realize that Axel was not the culprit and tells Jaden that Axel is Thelonious Viper's student.
The next day, Thelonious Viper gives every student a Bio-Band, which he had previously given to Jaden and Jesse before their Duel. He states they will be used during Survival Duels and that such Duels will be conducted without restrictions relating to dorm color or grade. He states that Duel data collected from the bands is sent to a terminal, where Viper can analyze it. Viper later tells Axel that he wants his first opponent to be Jaden. He says that he must make Jaden play seriously and use all of his power - even if it means that Axel would lose.
At the Obelisk Blue dorm, Adrian Gecko scans his Bio-Band and sends the data to a submarine near Duel Academy. His contact in the sub warns him not to take his eyes off of Viper. Thelonious Viper is now entering his lab again, and Adrian follows him, attempting to go in after him, but the door refuses to open for him. Viper comments that he believes that Jaden has more Duel energy than anyone else.
Syrus Truesdale becomes unsure of the survival duels and goes to confront Jaden about them. Jaden is unable to give an answer, and as Syrus runs off only Jesse appears to worry about the things he said. Syrus begins walking around the grounds and vows to Duel the first person he comes across - it ends up being Axel Brodie, whom he challenges. Upon hearing that Syrus is Jaden's best friend, Axel ties him up and suspends him from device he had previously been training on. Meanwhile, back to the Slifer dorm, Jesse and Hassleberry are argueing over Hassleberry's desk when Winged Kuriboh informs Jaden what has happened, and he, Jesse and Tyranno Hassleberry rush to Syrus' aide. Axel challenges Jaden and Jaden accepts in order to save Syrus.
Turn 2: Axel
Axel draws "Blaze Accelerator" and subsequently activates it. Now Axel, during each of his Main Phases, can send 1 Pyro-type monster with 500 or less ATK from his hand to the Graveyard to destroy one monster on Jaden's side of the field. If Axel activates the effect of "Blaze Accelerator", he will be forbidden from attacking the turn he activates this effect. Axel then activates the effect of "Blaze Accelerator" to send "Volcanic Shell" from his hand to the Graveyard and destroy "Flame Wingman", but Jaden activates his face-down "De-Fusion" to return "Flame Wingman" to his Fusion Deck and Special Summon "Avian" (1000/1000) and "Burstinatrix" (1200/800) from his Graveyard in Attack Position.
Since "Volcanic Shell" is in his Graveyard, Axel activates the effect of "Volcanic Shell" to pay 500 Life Points (Axel 4000 → 3500) and add another "Volcanic Shell" from his Deck to his hand. Axel then activates the effect of "Blaze Accelerator" to send "Volcanic Shell" from his hand to the Graveyard and destroy "Burstinatrix". Axel then Sets a card ("Firewall").