For me it turns out that what is actually confusing/unclear is a convention of using phrases "is played", "comes into play".
Hazard manifestations of Wizards say: "Discard this card if given Wizard comes into play."
Echo of All Joy is discarded when Doors of Night comes into play.
Does it mean that by short moment Alatar and Alatar the Hunter may be in play simultaneously?
Or that Echo of All Joy is discarded when Doors of Night is declared?
The problems should be discussed in separate thread. At the time of writing this post I did not gathered yet all materials needed for comparison and potentially affected by clarification/erratas.
