Shadow and Flame -/ X-Men 
Lillian Mulgrave has known she was a mutant since the age of twelve. She's been living at Xavier's School for the same length of time. Her mother, Katie Mulgrave nee Grey, had taken her to the school as soon as her powers manifested, wanting her daughter to be safe. It helped that Katie's sister, Jean, was a teacher there and could keep an eye on Lillian. See, Lillian's particular mutation allows her to have control over shadows. This led to her being called Shade - though her best friend Bobby wanted her to be Shady, to which she said that he should be Brain Freeze - by some of her peers. Lillian, while being a very quiet girl, managed to become friends with Bobby Drake shortly after he began attending the school, and Marie D'Ancanto - Rogue - and John Allerdyce followed soon after. They were the quartet, always around each other, always laughing.
Of course, it had to be ruined. The school was attacked. Mutants were kidnapped. And Lillian found herself in a (stolen, technically) car with her three best friends - one of whom she may or may not be in love with - and a surly man with impressive hair trying to figure out how to get them back.
Set during X-2
X-Series: Book One
Cover made by @peeta_4_ever