Fans of AMC's "The Walking Dead" may want to physically and emotionally prepare themselves for the upcoming season finale this Sunday. By all accounts, the episode is going to leave you all out of sorts due to its intensity and craziness.

While the character of Daryl Dixon is rarely phased by anything, the same cannot be said for actor Norman Reedus. The long time "Walking Dead" veteran revealed that he's seen an early version of the season six finale and, well, it's not pretty (in a good way).

"I saw a little rough cut of it," Reedus said. "And it's the most hardcore episode we've ever shot. I couldn't speak after I watched it. And, of course, I knew what was happening, and what was going to happen, and who was involved, but I got to tell you, I couldn't speak for like an hour. And then I just was bombarded with phone calls on my drive home. But that was a rough, rough, rough cut. I will say that it might be the best episode we've ever shot of the show."

It's rare for an episode to be so impactful that it leaves one of its stars speechless. But, then again, what else should we expect from the arrival of iconic comic book villain Negan? Though one of the main cast members may end up on the wrong side of Negan's barb wire wrapped baseball bat, Lucille, those that are still standing are excited to work with the great Jeffrey Dean Morgan.

"I've known Jeffrey for a long, long time," Reedus said. "He's a friend of mind, and I really respect him as an actor. And as a dude, he's just the best. It's weird to have such a nice guy playing such an a-hole, you know what I mean? But that's just the testament to how good he is. So I'm excited to see where he goes and what happens to that guy."

This week's episode will also be the second consecutive season finale directed by Greg Nicotero, who has quickly become AMC's No. 1 option for helming the most crucial episodes of "The Walking Dead."

"Talk about the inner circle, Greg's one of those people who's with you from the get-go," Reedus said. "From the very start of everything you do to the very end of everything you do. He's one of my best friends and I've watched that guy just blow the hell up. He's an unstoppable force right now on the show."

"The Walking Dead" will air its season six finale this Sunday on AMC at 9 pm ET.

Follow Brandon Katz at @Great_Katzby