Delivering Evil for Experts

I promised to avenge my parents.
But their killer is still on the loose, and he's stolen more than my parents' lives. Now, as he draws closer to his mysterious goals, he's poised to destroy what little I have left.
I promised to translate an ancient grimoire.
But it holds the secrets of my family--and the secret history of demon summoning. I fear its answers as much as I need them. Who was the foremother of Demonica...and who am I?
I promised to send my demon home.
But the way he watches me, the way he protects me, the way he touches me--how can I cast him away forever? I swore I would do this for him, but can I? Should I?
But I promised--and I will keep my promises even if they cost me my heart, my soul, and my life.