I should also consider if the user is confusing the name with another similar name. For example, Dillion Harper's brother is Albus Potter, so maybe there's confusion there. Alternatively, could it be a character from a different series where "One Night Only" is part of the title?
Alternatively, maybe there's a book or a merchandise item called "One Night Only" that features Dillion Harper from the "Harry Potter" expanded universe. Or perhaps it's related to the "Pottermore" platform where J.K. Rowling added more information about the characters. Dillion Harper is part of that expanded story, right? He's the son of Harry's godfather, Sirius Black, and another sibling, so his story was added later. dillion harper one night only
I might need to confirm whether "One Night Only" is an actual published work or event. Checking online, there are some mentions of a "Harry Potter" all-nighter event in 1999 where J.K. Rowling finished the first book. The event was called "One Night Only" and it was held on June 20th, 1998, but that might be conflating dates. Wait, the first book was published in 1997. Maybe the event was a charity event where some Harry Potter-related activities took place, and Dillion Harper is being referenced in a fan-made context. I should also consider if the user is