Epsilon

One of the world's most advanced robots. Like in the original work, he uses photon energy, harnessed from sunlight, as both a power source and a weapon. He refused to participate in the 39th Central Asian Conflict, stating "there is no justice in this fight," and faced public criticism as a result. Above all, he understands that what Dr. Newton, his creator, entrusted to him was the "eradication of war," and he instinctively avoids combat. He deeply comprehends that using photon energy as a weapon could easily obliterate an entire city, and he intends to use it only to protect others.

Later, as a demonstration against his refusal to be drafted, he is sent to the Kingdom of Persia under the pretext of post-war processing. There, he witnesses the tragic aftermath of war and takes in war orphans he meets, living with them in Australia. Although he faces harsh criticism from the public for "acting as a foster father despite being a robot who refused the draft," he is adored by the children and staff at the facility. In the war-torn area, he "processed" the remains of numerous robots stripped of their artificial intelligence using the destructive power of photon energy. From this experience and the ominous song mentioning "Bora" that one of the children from Persia, Vasily, sings, he senses something unsettling behind the conflict. After Brand's tragic death in avenging Mont Blanc, he warns other targeted robots to prevent further tragedies. Following Dr. Newton's death, he senses Hoffman's crisis and rescues him.

Initially, even Hercules, who should have been his ally, misunderstood him as a "coward" and mocked him with biting sarcasm. However, it was later acknowledged that Epsilon, who refused the draft, was right, and it was deemed that there was no reason for Epsilon to be targeted or avenged.

After the safe house isolating Epsilon is attacked by Abler and General Scott is killed, he senses danger approaching the children and returns to Australia. Entrusting the children's rescue to Hogan, he confronts Pluto himself. He manages to take one of Pluto's arms but deliberately lets him go, falsely claiming he "defeated" him. Later, to rescue Vasily, who was kidnapped by Abler seeking a rematch, he teams up with the guard robot Hogan to storm Beegelan Castle. In the snowy, adverse weather where he cannot fully utilize his photon energy, he engages in a rematch, gaining the upper hand at dawn and destroying Pluto with photon energy. However, he still attempts to persuade Sahad within Pluto, but Sahad's fear of Bora prevents it. When Bora targets Hogan and Vasily, he cuts off his own hand to protect them. After Pluto bites off his head, he is destroyed by Bora. Just before, he detaches both hands capable of creating barriers from his body, shielding Vasily and Hogan from the shockwave, and protecting them to the end. With his remaining thoughts, he leaves a message, "Please protect the Earth in my place," before disappearing.

His form is humanoid, resembling a European male in his twenties. He is a handsome man with long hair and an androgynous impression, wearing a black sweater-like garment, black slacks, and boots.

"World's Greatest Robot" Version

He has a design reminiscent of a tokusatsu hero with a cape and full-body tights. He works at an orphanage in Australia and is kind-hearted, adored by many children. Once, he attempted to sink Pluto into the seabed mud through a scheme, but due to the guilt of using cowardly means and his kindness that couldn't abandon even an enemy, he ended up saving Pluto, which led to his weakness being exposed. As a robot powered by photon energy, his power, which could be infinitely exerted as long as there was light, was a threat to Pluto. However, he was challenged to a fight on a day with bad weather when he couldn't replenish energy, and while protecting a child who couldn't escape in time, he met a tragic end by being destroyed. In the first anime series and "Astro Boy," he fights alongside Atom against Pluto. In "Astro Boy," due to the original version's androgynous atmosphere, he is depicted as a female environmental protection robot. In this version, he challenges Pluto in an underwater battle utilizing his expertise in natural environments, but Pluto uses an undersea volcano as a shield, and fearing the eruption and destruction of nature if he attacks, he is defeated.