What is faith?
For those without faith, faith is nothing. Whether it's religious belief or any other kind of faith, it's something unnecessary, so naturally, it's meaningless.
For those with faith, faith is everything—it's life, it's something more important than life itself. Faith can be varied, which is why the word "faith" exists as a way to encompass all of it.
For those with faith but who lack conviction, faith is something dispensable—something to be used when needed and discarded like an old shoe when not.
Yang Yi is someone who falls between having faith without conviction and having none at all. His purpose is revenge. Unless something unexpected happens, revenge is his faith, and he will carry it out to the end.