'Supernatural' is about to introduce a 'game-changer' that could reshape Season 13

Supernatural has already introduced the son of Satan in Season 13, but the twists don't stop there. According to Mark Pellegrino, who plays the devil himself, a new addition in episode 2 will dramatically alter the course of the show again -- and it's a character we've met before.

While Sam and Dean are busy bringing up Lucifer's baby, Jack, on earth, Lucifer and Mary are stuck in an alternate universe where the Winchesters were never born and Heaven and Hell went to war, leading to the destruction of... just about everything.

It's here that we re-meet Lucifer's brother, the archangel Michael (Christian Keyes), in a snazzy new meatsuit.

Original image has been replaced. Credit: Mashable

Much like their dynamic in Supernatural's main timeline, Pellegrino says that Lucifer and Michael's relationship is "contentious... But Michael brings some additional baggage to the relationship that Lucifer certainly wasn't expecting."

Not only does this version of Michael have different priorities from the one we previously met, Pellegrino says that he's also got the upper hand on Lucifer.

"If Michael was strong enough in the real world to subdue Lucifer, this one is strong enough in the alternate universe to tear Lucifer to shreds and to sort of be the one responsible for the condition of the alternate universe," he explains. "He's that powerful and he has a whole different set of ambitions and an agenda that he wants to fulfill. That's definitely a different Michael and definitely a game-changer."

Naturally, the devil is a character who is accustomed to getting his way -- and being the most powerful being in any room -- so will Michael's seemingly limitless power shake Lucifer's confidence?

"The one great thing about Lucifer -- I guess it's great, I'm going to call it great -- is his indomitable will, and he does have that," Pellegrino hedges. "But I do think that you are going to see someone out of his depths and understanding that that's the fact, but refusing to let the other person know it."

Supernatural airs Thursdays at 8 p.m. on The CW.