Flame by Alexandra Silva

Frederick Emsworth has closed himself off. In a world where your next breath could be your last, he’s a living, breathing weapon with no give. Brooding, volatile, and haunted, he has no want for love. Until he’s given the job of watching over his best friend’s sister. Georgina is fiery, driven, and everything that turns his world upside down. Now he’s caught between the ghost of his past, shadows that threaten them at every turn, and a love so consuming that it scorches with hate.

FREDDIE
I took a kiss and it stole my soul. Now, it doesn’t matter how far I pull away. To protect my swan and save her from the darkness inside me. It doesn’t matter how hard I push her away, because everything comes back to that
One moment. One kiss. One smile.
The more I resist, the greater my need for her becomes. It’s impossible to let her go and reckless to keep her when the world around us threatens her every heart beat. I watch her from the shadows and guard her from afar. There is nothing I won’t do to keep her alive. No line I won’t cross or blood I won’t spill. Because I’m not a monster, I’m the Devil that will destroy your soul if you go near mine.
I am a moth enthralled by her flame.
Leaving only one certainty in this war—Georgina is my destruction and my end.