I have already watch whole episode, and I have already watch the whole episode, from what i see in the ending a gumiho cant turn into human after 1000 years or until 9th tail was born, but the mistake is: In the episode 1 Shin Woo-yeo already have 9 tail, it's kind of funny. I was realize this part after replaying the first episode, I can't moving on after watch the end of episode (almost in tears)

Btw i love the whole story.