I Love Her (Slight Yandere!Killua X Reader)

(Y/N),an average girl.She doesn't talk much,doesn't have any close friend. One day,she meet Killua.She just pass him "Hello"she greet him. Since then,the ex-assassin curious about (Y/N). His dark side known by (Y/N).Then,what happen? She is interesting,i want to know her more -Killua- I feel sick when people surr...