Board Thread:Spoilers!/@comment-24674051-20150720164321/@comment-26175319-20151002172033

Based on the sneak peeks, Emma created a curse which requires a savior to break, that's pretty clear.

My two cents on this...

The group needed a savior to free Merlin. Sensing she was losing the battle to darkness, thus not being able to be a savior she created that cursed t to force someone to "rise" as a savior. She might have created that curse with her last glimpse of "light" before embrassing 100% the DO role or a specific event triggered her intentions.

The sneek peek implies Regina is the one, or at least she thinks she is meant to be, but my guess is that it will be Henry. He needed something, a push, to start believing himself he could be a savior.

On the fact that Regina most likely used the dagger to prevent Emma to identify herself as the savior knowing she is still battling her DO urges. Most likely Regina noted how Arthur put his hand on his sword when the DO was mentionned and felt it would be dangerous at somepoint  for Emma.