|Game||Tales of Destiny 2|
|Weight||106 lbs / 48 kg|
|Height||5'2.5" / 159 cm|
|Weapon||Sword / Dagger|
|Japanese Voice Actor||Hikaru Midorikawa|
Eighteen years after they died, Leon and Chaltier are brought back to life by a woman named Elrane. She asked for their help to rewrite the history of the world. However, Leon refused and was banished back to the world. He wandered throughout the world alone. As time passed, Stahn Aileron's tale became a legend and Leon's name was also marked in history, although as a traitor. For this, he donned a skull mask made from a dragon cranium, known for its defensive abilities against attacks and spells, to hide his identity. He also changed his fighting style. Originally wielding only one sword, Chaltier, in his right hand and a shield in the other, he now wields another sword in his other hand.
Leon later ends up in the prison of Darilsheid, where he eventually meets Stahn and Rutee's son, and his nephew, Kyle Dunamis, and his friend, Loni Dunamis, when they share the same prison. After hearing how Kyle wants to be a hero, Leon appears and lectures him about what it takes to be a hero. He eventually frees them both, but claims that he does not have a name, so Kyle is free to name him whatever he wants. He is given the new name Judas. After helping them escape the prison, he leaves them and wanders some more. He later reappears in Straylize Temple and saves Kyle and Philia Felice from Barbatos Goetia. Kyle asks him to join him in his quest to find the true meaning of being a hero. He agrees, and along with a young girl named Reala, he accompanies Kyle and Loni in their quest.
Their quest leads them to be transported through time to the future, where the world is not as peaceful as Kyle hoped it to be. Judas and Loni are separated from Kyle and Reala, and end up in Hope Town. They stay and befriend a woman excelling in archery, named Nanaly Fletcher. During their stay, Judas and Loni often mention Kyle and Reala, and when Nanaly leaves Hope Town for Aigrette, she returns bringing Kyle and Reala back. Judas rejoins the group, and they eventually make it back to the present time after a shocking revelation of Reala's identity. On the way, Nanaly is also dragged to their time, so she joins them as well. Eventually, they discover Elrane's intention, though Judas knew it all along, choosing to keep silent about it. Kyle's group confronts her in a parallel world where she is hailed as a savior. It is there Elrane reveals to Kyle's group about Judas's identity: he is Leon Magnus, the traitor of the five heroes: Stahn, Rutee, Philia, Garr, and Leon. Judas confirms the revelation, and later the group, except Reala, is sent to a dream world, which revolves around the past and how it would seem to make them happy. However, Reala intervenes and manages to snap Kyle, Loni, and Nanaly back to their senses and reality.
In Judas's dream world, he is taken back to the time when Elrane revived him. He remembers how he betrayed Stahn and the other heroes and eventually died. She asks him to side with her, but Judas keeps refusing. Kyle's group eventually intervenes. Elrane is enraged and asks if Kyle would accept a traitor like Leon. However, Loni and Nanaly declare that the group does not know the traitor known as Leon Magnus, but instead is helping their friend, Judas. Eventually, the group learns that history was changed by Elrane, so Reala transports the group, including Judas, to the past timeline to undo Elrane's changes.
While attempting to prevent Elrane's intervention within the timeline, the group has to work with the Earth generals that will become Swordians in the future, Dymlos, Atwight, Chaltier, Clemente, Igtenos, and Karell Berselius. They are also joined with Karell's supposed twin brother, who turns out to be his twin sister, Harold Berselius. They are later transported to Dycroft, during the time when Stahn defeated Kronos. Stahn and the others plunged their Swordians into the Eye of Atamoni to stop it, but their powers are not enough. Judas is about to stab his Swordian into the Eye when the group is confronted by Barbatos for one last time. Upon his defeat, Barbatos throws himself to the Eye of Atamoni, killing himself. With Barbatos's death, Judas is free to give his final words to Chaltier before eventually stabbing him into the Eye, destroying Aethersphere.
The group returns to the present time right after that event and confronts Elrane in the God's Egg. They fight and defeat her, only to revive Fortuna from her egg. The group defeats her and, due to her defeat, history will be rewritten as if Elrane never existed, so the group can start anew to prevent the already bleak future. As Judas is about to disappear, he wonders whether he will be rejected in time or still die under the name Leon Magnus. However, one thing for sure, he will never forget Kyle and their bond. Thus, Judas vanishes, and it is presumed he dies once again as Leon.
Tales of Hearts
Tales of the World: Narikiri Dungeon 3
Judas appears in the third installment of the Narikiri Dungeon series, along with his past life as Leon, although only one can be in the group at a time.
Tales of Fandom Gaiden
Judas acts as Harold's assistant in hosting the Tales of Fandom Gaiden DVD that came with Japanese pre-orders of Tales of the Abyss. Harold, together with Stahn, calls him Leon, though he tells them to call him Judas.
- While Kyle gives him name Judas out of random thinking, it is actually a reference to the biblical traitor Judas Iscariot, the apostle who betrayed Jesus Christ. This symbolizes how Leon betrayed Stahn and his friends.
- Leon's death is featured in the crossover game, Namco X Capcom, albeit slightly altered. In the game, he also returns as Judas by the hand of Dark Valkyrie, first as an enemy, but later joins the player's group as the final party member.