Board Thread:Show-Related Questions and Answers/@comment-26116863-20160926032200/@comment-26116863-20161007030839

So, you're saying Hades lied? Because he did say that they would literally be snuffed out of existence. They retconned it then. And in that case, there is little in-show reason why he couldn't came back, in theory. Why he shouldn't come back is another story. It would further weaken the threat of death on this show, for one thing.