Tell me - [Killua X Reader fanfic]

Killua Zoldyck, a world renowned assassin. He's also a hunter. Helping out his best friend Gon Freecs was his priority, until that voice in the back of his head kicked in. Why couldn't anyone else see it? You were so captivating. His heart wasn't supposed to beat so fast, according to Gon anyway. Thats why he could le...