TV-Series
Description
Nasiens is a young herbalist introduced in The Seven Deadly Sins: Four Knights of the Apocalypse, and later becomes a Holy Knight of Liones as a member of the Percival Platoon. They were raised by the human herbalist Ordo in Echo Gorge, also known as Sylvan Vale, after being discovered as a foundling. Ordo cultivated in Nasiens a deep thirst for knowledge and a love of herbology and chemistry. Following Ordo's death, Nasiens became withdrawn and reclusive, struggling to express emotions. Meeting Percival, whom Nasiens considers their first true friend, gradually helps them open up to others.

Nasiens possesses a reserved, analytical, and soft-spoken personality. They prefer to observe and evaluate situations before acting, which can make them appear guarded or mysterious. Despite a calm exterior, Nasiens harbors a profound sense of loyalty and dedication once they commit to a cause or person. This cautious nature is balanced by a strong drive to protect their allies, often putting others' needs before their own. Nasiens is also intensely curious about the natural world, especially poisonous plants, and is willing to test dangerous substances on their own body to develop remedies and antibodies, a trait that earns them the nickname the Mad Herbalist.

Nasiens is motivated by a desire to protect their companions and to understand their own origins. Early in the story, they are shown to be searching for meaning after Ordo's passing. As the narrative progresses, a primary motivation becomes saving Percival, who they consider their hero. After Percival is lost in battle, Nasiens dedicates two years to researching a way to revive him, demonstrating an unwavering commitment that drives much of their late-story development.

In the story, Nasiens serves as the tactical and intellectual anchor of the Percival Platoon. They provide critical support through alchemical remedies, healing potions, and debilitating poisons, often turning the tide of battle without direct physical confrontation. Nasiens acts as a voice of reason, offering calm analysis during crises. Their strategic mind becomes increasingly vital as the group faces the forces of Camelot and King Arthur.

Key relationships define Nasiens' arc. Percival is the central figure: Nasiens views him as a hero and the first person to truly accept them, which deepens into romantic love. This love becomes so powerful that it influences Nasiens' own identity. Fellow party members Donny and Anne are close companions, with Nasiens developing jealousy when Anne shows Percival affection. A significant relationship exists with their adoptive sister Dolores, a Giant who cared for them in the valley. Nasiens is later revealed to be the biological child of Fairy King King and Giant Queen Diane, a truth discovered during a journey to the Fairy Realm. This revelation redefines their sense of self and places them within the legacy of the original Seven Deadly Sins.

Nasiens undergoes substantial development. They begin as a guarded loner who conceals their feelings, struggling with self-doubt and isolation. Through bonds with Percival and the others, they learn to trust, express emotions, and accept support. The discovery of their fairy heritage forces a confrontation with identity. A key turning point occurs when Nasiens, who was born without a fixed gender like some fairies, chooses to become a woman as an affirmation of their love for Percival. This decision marks a shift from a passive, uncertain existence to an active, self-actualized role, culminating in Nasiens becoming a confident young woman and a decisive knight.

Notable abilities center on the unique power Mix Venom, which allows Nasiens to ingest any poison or toxic chemical, neutralize it internally, then replicate it or synthesize an antidote at will. This grants them offensive options in the form of debilitating toxins and supportive capabilities for healing and status ailment removal. Nasiens also dual-wields a shortsword and a dagger named Belladonna and Henbane. As a hybrid of Fairy and Giant, Nasiens later awakens inherited abilities: they can fly, sense the location of plants and minerals through the earth, and access the physical resilience of Giants. These powers make Nasiens a versatile combatant capable of both area control and frontline support if necessary.