OVA
Description
Genthru, also known as the Bomber, is a tall and lanky man with spiky blond hair, orange eyes, and an angular face framed by sharp glasses. He typically wears a long seafoam green cloak decorated with cross-shaped symbols, paired with a light blue scarf, giving him a distinctive and somewhat sinister appearance. He is the leader of a small group of Nen users that includes his two partners, Sub and Bara, and serves as the primary antagonist within the Greed Island game.

On the surface, Genthru initially presents himself as a friendly, cooperative, and helpful player. He offers warnings about the dangers of the game, specifically about a mysterious killer known as the Bomber, and works alongside large alliances of players to collect the rare cards needed to complete Greed Island. This persona is entirely a fabrication. In truth, Genthru is the Bomber himself, and his outward friendliness is a calculated act of manipulation. He is ruthless, egotistical, and lacks compassion for anyone outside of his own small team. He enjoys the fear he instills in others and is willing to commit mass murder without hesitation to achieve his goals. Genthru is highly intelligent, a master strategist who remains calm and composed even while executing brutal plans. He thrives on control and can become visibly shaken or enraged when situations do not unfold as he expects.

Genthru's primary motivation is to win Greed Island, a task for which he was hired by the billionaire Battera. He is completely self-oriented and sees other players only as tools or obstacles. His methods are efficient and cruel: he uses his infamy as the Bomber to terrorize others, steals cards by force or through elaborate deceptions, and eliminates anyone who gets in his way. Despite his general lack of empathy, he demonstrates a genuine and deep loyalty to his partners, Sub and Bara. This care is shown when he insists on sharing dangerous risks equally among the three and, after being defeated, immediately pleads with his captors to use a healing card on the injured Bara.

In the story of Greed Island, Genthru infiltrates a large player alliance led by a man named Nickes, spending five years pretending to be a trusted ally. During this time, he secretly uses his Nen ability, Countdown, to plant a time bomb on every member of the group. When the alliance finally collects a vast number of rare cards, Genthru reveals his true identity as the Bomber. He uses the threat of the bombs to force the members to hand over all their cards before detonating the explosives, killing nearly the entire group. Only one member, a Nen exorcist named Abengane, survives by removing his own bomb beforehand.

Following this massacre, Genthru and his partners continue to terrorize other players, seeking to collect the final few cards needed to win. His actions put him in direct conflict with the main protagonists, Gon and Killua. Genthru murders several members of Gon's alliance, which pushes Gon to challenge him directly. The two engage in a fierce one-on-one battle. Throughout the fight, Genthru proves to be a formidable combatant, easily overpowering Gon with his superior skill and strength. However, Gon has prepared a specific strategy to counter Genthru's abilities. Gon deliberately allows Genthru to blow off both of his hands, using the opening this creates to land a critical kick. He then traps the Bomber in a pit and defeats him with a powerful Jajanken attack. After his defeat, Abengane finds Genthru, touches him, and says the phrase "I caught the Bomber," which deactivates his Nen abilities.

Genthru is a skilled Nen user classified as a Conjurer. He possesses two primary explosive abilities. The first is Little Flower, which allows him to create a powerful explosion in his hand. He protects his own hand by enveloping it in a dense layer of aura, making this ability effective for close-range attacks. His second and more devastating ability is Countdown. By touching a person and saying the word Bomber, Genthru can conjure and plant a bomb on them. For the bomb to activate, he must then explain the details of his ability to the victim. Once active, the bomb is linked to the target's heartbeat and will detonate after a set number of beats, killing them. The bomb can only be detonated prematurely when Genthru, Sub, and Bara touch thumbs and say the word Release. The only known way to deactivate a Countdown bomb without being killed is for the victim to touch Genthru and say I caught the Bomber. Genthru's development in the story is limited, as he serves as a major obstacle for the protagonists to overcome. While he does not undergo a personal transformation, his defeat demonstrates his main weakness: his calculated cruelty is ultimately surpassed by Gon's raw, unpredictable determination. His fate after being captured and having his Nen exorcised is not addressed further.