My Guardian Snake

Bullied Leo loved Chloe. Derek kills Leo, whose soul enters a snake Chloe names "Emerald." As a snake, Leo protects Chloe from Derek. He mutates into a half-human, half-snake. A Shadow Organization attacks Chloe's bloodline. Leo transforms into a half-snake warrior, revealing his features. Chloe recognizes him: "You're... Leo?" Leo transforms back into a human with superpowers, crushes the organization, rescues Chloe. They kiss, Chloe calling him "the best boyfriend."