Snow Lily, formally All of Love, is the Servamp of Lust contracted to Misono Alicein. He appears as a blonde-haired, red-eyed vampire favoring striking pink and black attire, often accented by a white scarf and unbuttoned shirt. His contracted form manifests uniquely as a black and pink butterfly, the only Servamp to transform into an insect. A key element of his appearance is the pocket watch serving as his contract item with Misono; the original destroyed watch was replaced by one originating from Misono's birth mother.

His personality blends a cheerful, mischievous exterior with deep empathy and fierce protectiveness. He frequently attempts to strip in various situations, a habit irritating to Misono, yet this contrasts sharply with his profound care for others, especially abused or abandoned children whom he shelters at the Alicein mansion. This protective drive focuses intensely on Misono, fueled by a fear that revealing painful truths about Misono's past would trigger self-loathing. Consequently, he repeatedly erases or manipulates Misono's memories using a hand-based spell, a practice born from his desire to shield Misono from trauma.

Snow Lily has served the Alicein family for generations, originally contracted to Misono's grandfather, Mikage Alicein. Following Mikage's death, he immediately formed a new contract with Misono. His long history encompasses centuries of service and difficult decisions, including voting alongside other Servamps to eliminate their creator, viewing it as necessary. He also helped conceal the truth behind Mikuni Alicein's killing of his mother to protect Misono, an event leading to Lily suppressing Misono's memories for years.

Within the film's narrative, Lily faces significant conflict when Otogiri, a subclass under Tsubaki, impersonates him and exposes his memory manipulations to Misono. This betrayal causes Misono to sever their bond, enabling Otogiri to destroy Lily's pocket watch. The contract break forces Lily into a weakened state, releasing his Jinn and causing loss of control. In his inner world, manifesting as a female entity embodying his emotions, he confronts Misono with fears of rejection while Misono uncovers Lily's hidden memories, revealing Misono's origins as an illegitimate child and his birth mother's tragic death.

After Misono reconciles with these truths and reassures Lily of their bond, they renew their contract using a new pocket watch. This renewal stabilizes Lily, though he retains lingering trauma from the experience, including a temporary loss of his characteristic flamboyance and heightened vulnerability. Their relationship evolves into mutual trust, with Misono demonstrating maturity by gaining his father's permission to fight alongside Lily and their allies.

Lily's abilities encompass transformation between human and butterfly forms, memory manipulation, area concealment magic, and generating a large scythe for combat. Despite these powers, he is not a strong fighter, relying more on defensive and supportive magic. He maintains key relationships beyond Misono, including a respectful but complex dynamic with Mikuni Alicein and a familial connection to his fellow Servamps, particularly his older brother Doubt Doubt.