Shadowhunters: Demon Flame
"Lucy Dimitri, a noblewoman of modest means, is under pressure to find a fiancé soon to secure her future. Finding a suitable partner, however, is not as easy as finding a needle in a haystack. She is not as beautiful as her sister. Plus, with her ever-sarcastic remarks, she is always sidelined at every party.
One day, while returning home from her quest for a husband, Lucy finds a horrifying creature breaking into her house. The creature also murders her mother. When the creature attacks, her elder sister suddenly saves her with a power beyond comprehension. To make matters worse, a young man with angelic features arrives, slays the creature, and takes her to an academy.
What was the creature looking for? Why did it want to kill her? How did her sister acquire such power? Lucy must discover her true identity, for the young man believes that creatures from the underworld are hunting her or her sister. Perhaps even both."