User blog comment:Omega natsu2/Chapter 364: Tartarus Arc, Part 1: Immorality and Sinners, Predictions./@comment-8153438-20131219131955/@comment-24257713-20131219163936

Not exactly. As long as the OS are conscious and never utter their prayer, Zero won't come back. Remember, they're the keys and he's the lock; you know what happens.