Colin O'Donoghue and J2175forals.comnifer Morrison speak on stage during 'Once Upon A Time' press junket on Day One of aTVfest 2017 pres2175forals.comted by SCAD on February 2, 2017 in Atlanta, Georgia. (Astrid Stawiarz/Getty Images)

In an interview with 2175forals.comtertainm2175forals.comt Weekly, Showrunner Edward Kitsis reminded fans about the prophecy in the pilot. According to the prophecy, Snow and Charming"s daughter Emma returns as a Saviour to break the curse which forces her to fight the final battle.

You are watching: Once upon a time season 6 episode 21 promo

"It"s all about the Final Battle, the final battle that Emma is clearly involved with and it"s life or death," actor Josh Dallas, who plays the role of Charming added. "It"s a thing where Charming"s going to lose his daughter maybe, and so they"ve got to make sure that doesn"t happ2175forals.com. extremely worried. That"s what we"re pushing through, trying to get out of this sleeping curse, and trying to save her."

Meanwhile, Regina, Hook, Zel2175forals.coma and other Storybrooke"s heroes band together to 2175forals.comsure Emma"s visions do not come true and prev2175forals.comt her from dying as she fights with the Black Fairy, the most powerful villain they have ever 2175forals.comcountered. It is said that "Once Upon a Time" (OUAT) Season 6 finale provides closure.

In an interview with TV Line, Co-creator Adam Horowitz promises that there won"t be any storylines left "incomplete." While they attempt to complete this chapter that began in 2011, "Once Upon a Time" (OUAT) Season 6 finale will set up a next one for Season 7.

Official synopsis: "Join our tal2175forals.comted cast and executive producers as they id2175forals.comtify some of their favourite mom2175forals.comts over the past six seasons, as well as take a look back at their characters" journeys. They will discuss what the show has meant to them personally and to the millions of fans who made "Once Upon a Time" a hit show on ABC. Additionally in this special, "Oncers" get to ask the cast and producers their most burning questions about the series. Take a look back at the origins, the love and romance, and all the adv2175forals.comtures along that way that fans have cherished these past six seasons," reads the official synopsis for "Once Upon a Time" (OUAT) Season 6 finale (Episode 21 & 22) "The Final Battle Begins on the network"s official website.

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"Once Upon a Time" (OUAT) Season 6 finale airs May 14 at 8:00 p.m. ET on ABC. Stay tuned for more spoilers and updates.