The finale of "Once Upon A Time" season 4 was a complete turnaround. Emma exhibited the makings of a savior just before being turned into the dark one, taking the fall so Regina can get her happy ending. With Emma on the dark side, Regina is hoped to make a 360, too. 

Fans are hoping that Emma's selfless act will be enough for the evil queen to be not so evil this time, not only because a friend so important to her faced such a horrible fate but also because she does not shy away from actually doing good things and becoming a hero, too. 

It remains to be seen how Regina will go on with Emma going dark. But what the latter sacrificed for, which is Regina and Hood's forever, may be thrown away and it will be all because of Zelena, the Wicked Witch of the East who vowed to waylay Regina's love. 

The character is believed to be the new villain in "Once Upon A Time" season 5. That is a speculation at the moment, and if Josh Dallas, who plays Prince Charming, wasn't bluffing, Storybrooke is about to see what horrors the witch is capable of, should she step up to be the new adversary in the series. 

"The new big baddie is going to be really bad. It's the unimaginable. It's the worst thing that could possibly happen. It's going to be tough for everybody. It's going to be distressing for fans," the actor warned fans in an interview with Spinoff Online. 

As for Emma, executive producers Edward Kitsis and Adam Horowitz revealed that she won't be evil for long, provided Regina and the others are successful in finding the right person to help out. Merlin, as it turns out, is the only individual who can banish evil from Emma's system. According to Zap2it, the quest to find the legendary sorcerer will be an imperative in "Once Upon A Time" season 5, which will premiere in fall.