Yes, there might be. The Naruto fandom is quite large and diverse, and often crossovers with other popular series concepts like 'Killer Queen' from JoJo's Bizarre Adventure are created by fans in the form of fanfics. You can try searching on major fanfic platforms such as Archive of Our Own or Fanfiction.net.
A 'killer queen visual novel' likely has a story that focuses on the Killer Queen. It may explore her backstory, her motives, and her relationships. For example, it could be that she is a powerful figure in a world filled with chaos. The visual novel might use its art and narrative to bring out her character. There could be various plot twists and turns as the story progresses, and the reader gets to experience different aspects of this Killer Queen - centric world through different paths and choices within the visual novel.
It's unique because it allows for a fresh take on the Naruto story. By introducing Killer Queen's elements, the fanfiction can explore different character dynamics. For example, how would Naruto and his friends react to a character with Killer Queen's powers? Would they be allies or enemies? Also, the art style and concepts from JoJo's Bizarre Adventure can add a new aesthetic to the Naruto world, making it stand out from traditional Naruto fanfictions.
Obviously, the babysitter and the 'killer queen' are the main characters. The babysitter is likely an ordinary person who gets caught up in some extraordinary circumstances due to the 'killer queen'.
I'm not sure. It might be popular among fans of visual novels and those who like unique or edgy themes. However, if it's a relatively new or niche release, it may not have a wide - spread popularity yet.
The SCP Foundation is purely fictional. It's a collection of imaginative and often creepy stories and characters that are made up for entertainment purposes and have no basis in reality.