King--who, along with the rest of the band, is promoting Slayer's latest release, 2006's "Christ Illusion"--said he isn't sure who first proposed the idea of the co-headlining tour, but it was something Slayer's manager had brought up before.

"He was talking to me about it all the time. I was always on the fence because I didn't know where Manson was these days, [or] what he was going to bring to the show. I never met him. I just met him for the first time a couple of weeks ago. He's a very smart dude, as you can imagine, and he carries his own absinthe around, so me and him are going to get along fine," King said with a laugh.

Manson will close every show on the upcoming tour, King said.

"We're splitting production, stage, everything else. When we play, none of his stuff's on there. When he plays, none of our stuff's on there. He wanted to [go on after us]. I said, "Cool, man." I like not playing last all the time. We're playing the same amount of time so, essentially, we get to wear out the crowd. By the time we're done and he gets on stage, I'm already backstage and having a shot with my buddies."

Speaking of camaraderie, that played a big part in the recording of Slayer's latest album, last year's "Christ Illusion." It was the first album in years that Slayer recorded with drummer Dave Lombardo, who returned to the band in 2002.

"There was no weirdness about it because we're already used to each other again," King said.

King thinks the reunion is especially cool for his fans.

"I think the best part is the fans who got onboard in the '90s and never got to see us play with [him]. That's the biggest high. They get to see us play with somebody they wanted to see forever," King said.

"[Lombardo] was around the first nine or 10 years [of the band], and he was gone for 12. Now, if we keep him until we're done, that's a nice way to finish things up."

King said, however, he doesn't have any plans to break up Slayer.

"I don't have any idea when that's going to be. The only farewell plans we have is when we do it, we're going to do it and that's going to be it. We're not going to do the farewell tour sequel or anything like that. If you want to come see us, you better come now because we're not coming back. I just think it's so phony when people do that. How many times has KISS done it? How many times has everyone done it? Like, are you really going away this time, or do you want more of my money?"