- "I gotta tell you, I've been looking forward to meeting you for a long time. I'm a huge fan. John Wick. And so far, you haven't disappointed."
Zero was an assassin employed by the Adjudicator and the leader and mentor of his own group of assassins. He is the central antagonist and a major opponent in John Wick: Chapter 3 – Parabellum, during which he fights against protagonist John Wick on several occasions.
Zero is the leader and mentor to a group of ninja-assassins based in New York City. When not teaching or taking up assassination work, he runs a street-food sushi restaurant alongside his students. He is a fan of John Wick.
John Wick: Chapter 3 - Parabellum
Zero and his students are first tasked with raiding Ruska Roma, which had aided John Wick's departure from the country to Casablanca. They swiftly dispatching the Director's guards and interrupt the ballet rehearsal. The Adjudicator arrives and demands that the Director to reaffirm her loyalty to the High Table and that her penance must be paid in blood. She tells the Director to hold out her "helping hands" and Zero stabs her hands with his sword.
Shortly after, Zero and his students attack The Soup Kitchen. They quickly overpower the defenders and eventually fight their a way to the rooftop where the Bowery King waited for them. The Bowery King pledges his fealty to the High Table, but the Adjudicator tells him he had his chance to step down. The Adjudicator then tells him that for the seven bullets he gave to John to aid him in killing Santino D'Antonio, the Bowery King will receive seven cuts, which are carried out by Zero with his sword.
After John returns from his meeting with the Elder, Zero's students confront the ex-hitman in Grand Central Station, killing off rival assassins before trying to kill him, but John fights them off and flees to the Continental on motorcycles. Zero pursues him there but before he could kill him he is stopped by Charon, who informs him that no business is to take place on Continental grounds, as John had placed his hand on the stairs leading to the front door.
John then goes inside to meet with Winston and seat down on a couch while waiting for Charon to go and get him. Zero attempts to sit down next to John but the latter moves to a chair to get away from him. Zero then tells John Wick that he is a big fan of his "work" and that they are both the same as "masters of death", but John rebukes the latter part.
Later, after Winston refuses to step down as manager of the Continental and John Wick agrees to defend him. Zero is instructed by the Adjudicator to kill both of them, and informs him that mercenaries will be sent by the High Table to assist in the task. However, John manages to fight through Zero's men and two of his top students, the Shinobi, before facing off with Zero himself. After an intense duel between the two, John defeats Zero by stabbing him through the chest with sword. As the two lay exhausted, Zero compliments John on his skills and states it was an honor and it was a good fight, to which John agrees that it was a good fight. As John gets up and walks away, Zero states that he'll catch up with him later, to which John deadpans that he wouldn't. Just as John is leaving, Zero slumps over and succumbs to his wound.
- "We're both masters of death."
Despite his job as an enforcer, Zero does not seem to let it affect his personal life. He seems to take extraordinary enjoyment from fighting, and both he and some of his students are big fans of John Wick to the point that they let him recover between fights instead of hitting him when he's open; during their fight in The Continental, he quickly admitted to Wick that he's a huge fan of the latter's work and abilities. He seems to have a high respect for Wick.
- Peak Human Condition: Zero has shown to be in excellent condition, being a top-tier assassin with years of training. His strength, speed, agility and endurance being on par with that of John Wick.
- Master Assassin: Zero was an extraordinarily skilled assassin. The Adjudicator herself held him in high regard, believing that he could defeat even John Wick. Despite ultimately losing, Zero proved to be of equal skill to John, giving him a harder fight than any of his previous enemies.
- Master Martial Artist: Zero is a highly skilled martial artist and equally skilled as John Wick, being able to hold his own against the legendary assassin. His fighting style consists of Wun Hop Kuen Do, Muay Thai, Capoeira, Pencak Silat and multiples disciplines of Ninjutsu.
- Master Swordsman: Zero carries a katana, which resembles a wakizashi, with him at all times, and shows extraordinary skill with the weapon. He makes use of quick and swift slashes to kill his opponents. Though skilled with a sword, even Zero, John's most equally matched opponent, was still unable to defeat John even when armed.
- Skilled Chef: As Zero is a street-food sushi chef in his spare time, it can be assumed that he is a talented chef.
- The fact that Zero is a street-food sushi-chef in his free time seems to be an allusion to the fact that actor Mark Dacascos is the presenter of Iron Chef America in real life.