Oenanthe (Various Black Butler x Chubby! Rea...
You are the Queen's Oenanthe. (Oenanthe is a species of deadly plant that originates in the UK. It convulses your organs and limbs, but also forces you to smile while you are dying. That's called the Sardonic Grin.) You basically kill whoever is in the way for Her Majesty. You are a noble, running your family's porcelain company, despite the fact you're 15. The Queen assigns you to solve some cases with her Guard Dog- Ciel Phantomhive.
(Things go on from here as they do in the manga/anime. A few people, such as Ciel and Alois, will be a bit older, but things happen the same. Kinda. This is my first fan fiction! Feedback and constructive criticism are welcome. The reader is female. Enjoy!)