Ash Blake is the central protagonist of his story, a sixteen-year-old student at Ansullivan Dragonar Academy who is known from the outset as the school's number one problem child. This reputation stems from two primary factors: his unusual and volatile temper, and the fact that he is the only student in the academy whose personal dragon, or Pal, has failed to appear. Despite bearing a large and ornate Star Brand on his left arm that marks him as a future dragon master, his lack of a partner has made him a target for ridicule, a slight to which he reacts violently, especially when it concerns his absent dragon.

His background is marked by a significant childhood event that explains his unique circumstances. Years prior, during the Orphan Rite where young hopefuls seek to be chosen by the Mother Dragon, Ash met a determined girl named Silvia Lautreamont. When the Mother Dragon chose Ash instead of Silvia, he defied the sacred ritual and transferred the powerful dragon Lancelot to her. This act of selflessness resulted in a catastrophic explosion that destroyed his left arm. To save his life, the Mother Dragon grafted a new arm onto him and bestowed him with a different dragon, one of immense power and significance, named Eco. The trauma of this event erased most of his memories of that day, but left him with a powerful and unique ability known as the Chalice, which grants him the rare talent to ride and command any dragon, regardless of its original master. His Star Brand, which covers his entire left arm, is a constant physical reminder of this past and is typically kept hidden beneath bandages.

In terms of personality, Ash is fundamentally kind, hardworking, and fiercely loyal. While he is generally easygoing and tolerant of insults directed at himself, he possesses a hair-trigger temper when his friends, and especially his dragon, are insulted, often escalating conflicts until an apology is given. This unwavering sense of justice often puts him at odds with nobles and royalty, whom he will confront directly without regard for their status, a trait that earns him both respect and notoriety. Despite being at the center of numerous romantic misadventures and finding himself surrounded by an ever-growing harem of female admirers, he is portrayed as being genuinely oblivious to their affections, more focused on his duties as a Dragonar. He is also notably poor at telling lies, often leading to awkward and comedic situations.

Ash's role in the story is that of the heroic underdog who rises to greatness. Initially an outcast, his life changes forever when his dragon, Eco, finally awakens in the form of a beautiful and haughty girl who declares herself his master. Their reluctant partnership is the core of the narrative. After saving his town from a rampaging undead dragon, the Necromancia, Ash is hailed as a hero and given the title of the Silver Knight, which carries a noble rank and dramatically shifts public perception of him from problem child to celebrated figure. This event leads to him being officially knighted and joining the student council, where he serves as secretary and is groomed by the student president, Rebecca Randall, to one day take her place as a leader. He is later revealed to be the Knight of Avalon, the destined master of Eco, who is herself the Imperial Princess of the Avalon Holy Dragons.

His key relationships are central to his development. His bond with Eco is the most important; it is a volatile partnership where she constantly asserts her dominance, but their mutual reliance grows into deep affection as they face dangers together. His dynamic with Princess Silvia begins with bitter rivalry but transforms into a close romantic bond after she discovers he was the boy who sacrificed his future for her years ago. He also shares a significant mentor-student relationship with the powerful student council president, Rebecca Randall, who believes in his potential and encourages his growth. His unique ability to ride any dragon and his heroic deeds inadvertently attract a wide circle of admirers, including nobles, princesses, and priestesses, all of whom develop romantic feelings for him.

Throughout the story, Ash develops from a frustrated loner into a proven hero and leader. He is an Arc Dragonar, a rider of the highest order, capable of summoning powerful magical armor known as Ark. With Eco's help, he can access a vast archive of Ark blueprints, allowing him to adapt to various combat situations. His most notable abilities include his unique power to ride any dragon, his exceptional combat instincts that allow him to outwit powerful enemies, and his ability to wield legendary weapons such as the holy sword Excalibur. Over time, his power grows to the point where his Star Brand can spread across his entire body, and he eventually gains a completed, personal Ark that allows him to fight as a true Knight of Avalon.