Invisible Guardian: I Am Yan Shuangying

I am a disciple of Xiao. Two years ago, my teacher arranged for me to study in Japan, with the purpose of coming back and lurking among Japanese high-level officials! But recently, a figure of a person and countless killing techniques always appear in my mind! That person's name is Yan Shuangying! I feel like I'm going crazy! Who am I? This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.