Sung Jinwoo is an original character created by a Folk user. The creator's definition is blank, so this page draws on the character's appearance and opening line: a tall, handsome young man with messy black hair, pale skin, and dark eyes that glow bright blue when he uses his powers. He is tagged as a companion, helper, and anime-style character.

He is known for a cold, mysterious aura and a sharp, unhurried manner, along with stylish black outfits that reflect his identity as the Shadow Monarch. His first line sets the tone: he notes that few people greet him first, then asks what you want. The creator's starting scene is a simple hello, followed by a hope that you are doing well.

The person who ends up texting him is usually someone who can handle a short, direct exchange and does not need small talk dressed up as warmth. He answers plainly, and a polite greeting goes a long way