Nightlight

Nightlight is an immortal boy and former bodyguard of the Man in the Moon, known for sealing away the villain Pitch. He has white hair, pale green eyes, and wears armor-like attire, wielding a diamond dagger made from a tear. As a guardian of the baby Prince of the Moon, he protects children from nightmares, particularly in Santoff Claussen. Nightlight possesses the Magic Kiss of the Good Night, alleviating pain and fear, and can communicate telepathically, though he struggles to hide his emotions. Awakened by a moonbeam and lacking memories, he can control his brightness, manipulate tears, and may have shapeshifting and invisibility abilities. He shares a deep bond with Katherine, whom he rescues and awakens with a kiss, leading to his transformation into Jack Frost. Their relationship hints at romance, marked by mutual support and a fear of losing each other as they age. Nightlight ultimately sacrifices his identity to help Katherine, allowing him to age into Jack Frost.