alien race with dragon like creatures invade earth, kill 1b people

i read this in middle school, somewhere around 2015 i'm guessing. it's from the perspective of a boy, living in china with his mom, and out of nowhere an alien race invades, and wipes out a billion people. one of the "dragons" comes face to face with him, but does nothing to eradicate him. he finds out his estranged father is part of said alien race, and that's why he was spared, the dragon recognised his scent or something. this is all i can recall, but please for the love of god help me find this, i have been scouring the internet for hours. i think it may be a chinese translation? because there is nothing similar i can find. i remember the cover being blue-ish