The secret Slayer show at The Sinclair a couple months back was one of the hottest tickets in town and proved one of the more memorable nights in recent Boston metal history. But for Slayer frontman Kerry King, the Converse Rubber Tracks show was just another gig.

“I don’t remember much about it,” he tells DigBoston from a recent Mayhem Festival stop in Milwaukee. “The only thing I remember about that show is their somewhat animated video backdrop.”

He was referring to the scrolling graffiti screen provided by Converse, which stood out because it was a big departure from the usual blasphemous video imagery that usually accompanies a Slayer show.

Backdrops aside, the Sinclair show was a stark reminder that Slayer is one of the few bands – in metal or any genre, really – that can effortlessly eviscerate just about any venue. No matter where you see them – and Saturday it will be headlining the Xfinity Center in Mansfield for the all-day Rockstar Mayhem Festival – they make one thing clear: they are the loudest, fastest, most badass speed metal band to have ever graced this planet.

“We are rolling with the biggest show we have ever taken anywhere,” he says. “Being the sole headliner, we felt that we had to bring it. Visually it’s the biggest show we’ve ever done.”

The legendary Bay Area thrash band are still settling in with guitarist Gary Holt and drummer Paul Bostaph, who replaced the late Jeff Hanneman and ex-drummer Dave Lombardo, both of whom were founding members. The band’s upcoming new album, Repentless, comes out in September and is Bostaph’s first with Slayer since 2001 and the first ever without Hanneman, who died of liver failure in 2013.

“For Gary, I thought a very long time about how I wanted to incorporate Gary,” King explains. “I didn’t think Slayer fans, as awesome and loyal as they are, were ready for someone outside the circle to contribute to this record. At the same time, I wanted Gary to feel like he contributed. So we landed on him doing solos. I think the recording is awesome and live it’s awesome. It’s got to be awesome for him to be playing solos he wrote and not just playing covers anymore.”

The band is also transitioning to a new label after nearly three decades with Rick Rubin’s American, signing instead with German metal powerhouse Nuclear Blast. “Their offer wasn’t even in the same ballpark, which I expected,” he says of Rubin’s label. “Beyond financially, I liked Nuclear Blast. Nuclear Blast is a place where [employees] go to get paid and they love it.”

As for Mayhem, it’s Slayer’s third headlining run on the annual summer festival. They’ll be joined on the main stage by King Diamond, Hellyeah, and Dayton, Ohio metalcore stalwarts The Devil Wears Prada. The second stage lineup includes White Chapel, Thy Art Is Murder, Jungle Rot, female-fronted Swedish band Sister Sin and Shattered Sun. “In my mind, Mayhem is just the new Ozzfest. It’s the exact same fucking bands, without Black Sabbath or Ozzy,” he says, laughing. “At the end of the day, there will be the next Mayhem. That’s what happened to Ozzfest. They ran out of bands. The cycle runs out.”

King talks openly and occasionally jousts with the press, such as when he recently made comments about not liking the music of mysterious Satan-worshipping Swedish band Ghost. The story went viral, but King said it was overblown.

“The problem with doing interviews is that whoever you’re doing the interview with may or may not have bad intentions,” he says. “They didn’t see the part where I said they were wonderful dudes. I said I love the imagery. I tried to like their music, but it’s just not my thing. Somehow that became ‘Kerry King hates fucking Ghost.’ Whatever I say is just taken out of context for the furthering of whatever crappy website they write for.”