Read manga: I've Waited For The Fairy Teacher For Hundreds Of Years

manga
Summary:

I'll wait for you for as long as forever. Fairy Teacher Xing Li is on a mission to seal an evil relic when he falls into the Mortal Realm and loses his memory. Nuo Qing, his self-proclaimed disciple, takes him home. But only when an old friend visits does Xing Li realize that Nuo Qing has been waiting hundreds of years for him?