Age, the protagonist of Heroic Age, is a character whose very existence bridges the vast gap between humanity and the godlike beings that shape the universe. His background is profoundly unique, as he was not raised in any human society. Instead, he was nurtured by the enigmatic Golden Tribe, whom he refers to as his fathers, on the desolate, ruined planet of Oron. The only other presence in his solitary upbringing was the artificial intelligence of a crashed spaceship, which he affectionately called his mother. This unconventional origin means that while Age possesses the body and appearance of a sixteen-year-old boy, his chronological age is far greater, estimated to be around one hundred and twenty years, much of which he spent in isolation. As a result of being raised outside of civilization by a transcendent race, his knowledge of basic human concepts, including numbers, gender, and social customs, is virtually nonexistent.

In terms of personality, Age is defined by a striking contrast between his feral upbringing and an innate, pure-hearted goodness. He is often described as wild and childlike, earning him the nickname monkey from the crew of the starship Argonaut. He is naturally self-sufficient, capable of hunting and surviving on his own, yet he approaches the world with an open and friendly disposition. Age lacks guile or malice; his actions are driven by simple, direct emotions rather than complex strategies or personal ambition. This innocence allows him to connect with others in ways that more jaded characters cannot, and he is known for his artistic side, often expressing himself by painting elaborate murals that have a tendency to depict future events. His motivations are initially simple, primarily focused on the desire to fulfill the one request he has for the humans who seek his help: restoring his ruined home planet of Oron to its former lush and peaceful state. However, as the story progresses, his bond with Princess Dhianeila becomes the central driving force behind his actions, shifting his purpose from a simple contract to a profound personal commitment.

Age’s role in the story is that of humanity's prophesied champion. As a Nodos, he carries within his body the essence of the strongest of the Heroic Tribe, a being named Bellcross. This allows him to transform into a colossal, humanoid entity of immense power, which he uses to battle the forces of the Silver and Bronze Tribes who threaten the existence of the Iron Tribe, humanity. He is bound to Princess Dhianeila by a set of twelve ancient contracts or labors, which dictate his service to her and humanity, including reclaiming Earth, defeating the other Heroic Tribe members, and ensuring humanity becomes the ruler of the universe. His key relationships are central to his development. His connection with Dhianeila is the most significant; she is the first person to truly reach him, and he is the only one who can enter her absolute defense zone. She serves as his anchor, the one person who can pull him back from his destructive rages and guide his immense power. His relationship with the Argonaut’s crew, particularly the initially distrustful knight Iolaous, evolves as they come to accept him not just as a living weapon, but as a comrade.

Age’s development throughout the series is subtle but crucial. He begins as a pure, almost feral wild child with no understanding of his own significance or the wider universe. Through his interactions with Dhianeila and the crew of the Argonaut, he gains a sense of purpose and belonging that extends beyond his simple wish to restore his planet. He learns to value the bonds he forms, and his initial instinct-driven combat style becomes tempered by a desire to protect those who have accepted him. His journey transforms him from a lonely boy following a preordained contract into a hero who fights for a future he has chosen to share with others.

Notable abilities are the hallmark of Age’s character. In his human form, he possesses superhuman strength and agility, capable of tearing through the metal hull of a starship with his bare hands. However, his true power is unleashed when he transforms into Bellcross, a towering blue being of immense might. Bellcross is considered the strongest of the remaining Heroic Tribe, and his core ability is said to be existence itself. This power makes him nearly indestructible and absolute within the flow of space-time, to the point where another Nodos who can travel through parallel timelines was unable to find a single reality where she could successfully kill him. His combat abilities include firing powerful energy blasts from his mouth, absorbing the life force of his enemies and redirecting it as destructive energy, and unleashing a berserker rage state when pushed to his limits. In this frenzied state, his power escalates to apocalyptic levels, releasing shockwaves that can destroy nearby fleets and potentially escalate to the scale of a supernova, but at the cost of losing his sense of self and becoming a danger to both friend and foe.