When it comes to big bads, the Winchester brothers have fought the best of them. From angry spirits to Lucifer himself, they know what it takes to defeat evil. Heck, they even stopped the apocalypse.

And yet, when Supernatural‘s 10th season came to a close, Sam and Dean released what might be the greatest foe they’ve ever faced: the Darkness. According to Death, the Darkness was an evil that God defeated and locked away many years ago. And by many, we’re talking a pre-Biblical battle. So when season 11 begins, what will the Darkness look like?

WATCH: EW’s Sam Highfill on the potential of a shirtless car-wash scene on Supernatural

“As of right now we have it built as one specific entity, obviously that would be a character that we’re introducing,” Jensen Ackles revealed. “But whatever the reach of that character, what that character can do, we’re not quite sure of.”

However, Ackles did add that, “We don’t know the scope of her powers.” In other words, this show could be facing its biggest, baddest female character yet.

“This one’s interesting because it’s not really a monster,” Ackles said. “It’s more of a primal force that we know nothing about. There’s no lore; there’s no guidebook; there’s no instruction manual on how to deal with this.”

In other words: good luck, boys.

Supernatural returns Wednesday, Oct. 7 at 9 p.m. ET on The CW.

Image zoom EW

From now until our huge fall TV preview hits newsstands Sept. 10, EW is bringing you 50 scoops in 50 days. Follow the hashtag #50Scoops50Days on Twitter and Instagram to keep up with the latest, and check EW.com/50Scoops50Days for all the news and surprises.