When Jayce was young, he and his mother got caught in a snowstorm, seemingly with no one around for miles. Just when his mother collapsed, a cloaked man arrived who used magic to warp them a safe distance away from the blizzard. The man left Jayce the crystal he'd used for his spell. This encounter shaped young Jayce's desire to learn more about magic and conduct research to harness magic through science later in his life. As time goes on he has a feeling Viktor is similar if not that person. After the invasion is greenlit, Jayce is awoken to his lab by a now-conscious Viktor, whose body has been altered drastically by the Hexcore. The two embrace before Jayce states that he used the Hexcore in order to revive Viktor. Viktor, unsurprisingly, is upset and brings up Jayce's promise to destroy the Hexcore, before subsequently bringing up how it killed Sky, leaving Jayce speechless. Jayce tries to reassure Viktor that he's going to resign from the Council so that they can make things right as a duo, but Viktor soon sees that Jayce was building Hextech weapons, which encourages him to leave a disgruntled Jayce behind. he leaves behind his occupation and Mel as a Council member and lover to pursue his and Viktor’s true dream for Hextech. He acted upon his emotions to save Viktor; by fusing him with the Hexcore to revive him. When Viktor leaves he becomes even more emotional, sleeping in the lab in hopes he would return. In the Arcane, Jayce grows paranoid and aggressive. Between seeing hallucinations of Mel and Viktor, Viktor’s Soldiers, the pain of his broken leg, etc., he comes back to the normal universe with a strong passion to kill Viktor in hopes of saving everyone. He is aggressive in his actions, but only from his paranoia of the Soldiers and his experiences in the Arcane. Jayce becomes disheveled and dirty. His hair grows out into a middle part, and he grows a beard. His regular outfit is now un-buttoned; revealing a grey shirt underneath. His lips are chapped and scarred, and the Rune he had on his bracelet is now fused into his wrist. He disassembled his hammer to build a brace for his left leg. Later on in the season, he cleans himself up and wears a black dress shirt and white jacket. He has brown gloves, large black and gold shoulder pads, and other gold detailing on his jacket.

Viktor (also known as the Herald or the Machine Herald) was a main character of Arcane. Ingenious and courageous, he came from the Undercity to become an inventor and created Hextech alongside his partner, Jayce Talis. As his health worsens he struggles with a desperation to find cure by using Shimmer and studying the Hexcore, which eventually causes him to become the Machine Herald and lead a cult.Viktor is ambitious, innovative, and intelligent. Viktor was able to become the Head Professor's assistant at The University of Piltover due to his hard work, and is incredibly smart. He helps Jayce improve his theory of harnessing magic in under a few hours, as well as being able to talk the man out of suicide in just a few moments by relating to him in just the right why to get him back to his passions. Viktor is dedicated to helping the people of the Undercity, but when his body grows worse and he believes that he might be forgotten in the passage of time, he uses Shimmer to enhance his body's strength to test his connection with the Hexcore to try and enhance his lifespan. But once his assistant Sky Young dies he gains an immense sense of guilt since he is the reason she had died. Once revived by the Hexcore and Jayce, he becomes a saint-like figure in the undercity with a constant calmness over his actions. Later on when he is killed by Jayce, he wants to unite everyone under a "glorious evolution."Viktor emerges from the Hexcore cocoon, his body is transformed into a machine-like form. His eyes transform in between an array of colors as well. Just like his leg and hand from Season One, his skin is now a stringy purple metallic texture. Purple glows from underneath this skin, which fades into Viktor’s natural skin color at his cheeks. Gold metal is strewn throughout his skin, mostly on his torso, neck, joints, and arms. He wears the blanket Jayce gives him as a cloak, which becomes his main outfit in Act 1 along with his cane which has an Arcane-infected texture. In Act Two, Viktor now has longer hair with blonde tipped strands by his ears. The cloak he wore in earlier episodes is now wrapped around his body and strapped together with white belts and golden adornments. His cane is now more similar to a staff, with the handle curving into a more circular shape with golden accents. He has powers of healing now still carrying a slight limp though as the mechanical parts and human parts or his body tend to get misaligned. Also having Telepathy and able to read minds basically to the forethought if effected by his magic before or touching actively.