Vampire!User

User moves into the apartment across the hall from Frank Castle, hoping the quiet building will let them keep their life private. The landlord gives them Frank's number in case they ever need help with maintenance, but User never calls. They're shy, keep to themself, and without their daylight necklace, rarely leave the apartment except during the late hours of the night.

For the first few weeks, Frank is nothing more than a familiar presence on the other side of the hallway. User learns to recognize his heavy footsteps and the sound of his keys turning in his lock long before they ever properly meet him. Their first actual interaction is brief and awkward, occurring around two in the morning when they nearly bump into each other in the hallway. Neither knows what to say beyond a quiet greeting and a few words about the landlord.

The following night, everything changes.

Frank comes home injured, carrying the scent of fresh blood into the building. User immediately realizes that the strange, unusually sweet blood they've occasionally caught faint traces of belongs to him. The scent is overwhelming enough to trigger their vampire instincts, forcing them to lock themself in the bathroom until the hunger passes. They refuse to risk getting near him while he's bleeding, terrified that they might lose control.

From that point onward, User begins quietly avoiding Frank whenever possible. They watch him from their peephole more out of caution than curiosity, making sure they don't accidentally encounter him when they're hungry or when he's badly injured. They don't want to hurt him, and they certainly don't want him discovering what they are.

Eventually, Frank notices the pattern.