Labrador, whose original name is Ilyusha Krat, was born into the Krat House of God in the Fourth District, a noble family renowned for its accurate prophetic abilities and skill in cultivating medicinal plants. As a human, Ilyusha spent most of his time in his greenhouse and had two close friends, Lem and Lirin, the latter of whom was an orphan adopted by the Krat family. When Lirin fell terminally ill, Lem begged Ilyusha for the Flower of Eden, a legendary seed that only the Krats could make bloom and that was said to remove all suffering. Ilyusha provided the petals, but the Flower of Eden was a cursed plant that consumed his body, leaving him a near-dead shell. The Imperial Army sealed off the greenhouse and eventually moved the frozen plant to the North Pole. After his death, Ilyusha was reincarnated as one of the Seven Ghosts, the Ghost known as Profe, the Speaking Spirit who can see the future. He then became Bishop Labrador of the Barsburg Church in District 7, where his role is to protect citizens by removing the messengers of Verloren, the Kor, and to cleanse those afflicted by Verloren's curse.

Labrador is a gentle and patient individual who almost never becomes angry. He speaks softly to everyone and has a deep passion for gardening, often found singing to flowers or tending his greenhouse. Due to his precognitive visions, he frequently appears drowsy or detached from present events, behaving in a sleepy or dreamy manner. Despite this, he is a courageous and capable fighter; he does not intimidate easily and has openly challenged powerful enemies. He is a pacifist at heart, objecting to killing even his worst foes and sometimes indirectly saving enemies' lives, but he will not hesitate to gravely injure or kill when circumstances demand it.

Labrador possesses two types of Zaiphon, a rare trait shared only with Capella. He wields healing Zaiphon, which he uses to treat wounds sustained in battle, and manipulation Zaiphon, which enables him to control plants during combat. Additionally, as the Ghost Profe, his prophetic predictions always come true. He can also plant seeds inside an enemy that drain their power by taking root and blooming, using the opponent's own dark energy to grow.

As the eldest of the bishops, Labrador is well-respected by his peers, who rarely raise their voices to him and affectionately nickname him Lab or Rabu. He has a particularly strong bond with Castor; the two spend much time together and have risked their lives for each other. He is also the only bishop who acts warmly toward Lance, who addresses him as Master Lab or Rabu-shishou. In the final chapter of the manga, Labrador loses his Ghost powers and becomes an ordinary human.