They have amassed over three billion streams and more than two billion video views - so when rock band Five Finger Death Punch, who have quickly become one of America's biggest rock bands, announced a tour date in Wales, it is no surprise the gig at the Motorpoint arena was quick to sell out.

Zoltan is the band's guitarist Credit: PA Images

Formed in 2005, the band's first album sold more than 500,000 copies in the United States. Their second album a few years later helped grow their popularity, selling more than a million copies.

But with that rapid success and the pressures of touring, came some internal struggles within the band, guitarist Zoltan Bathory told ITV News' Mike Griffiths.

The band's guitarist Zoltan spoke to ITV News ahead of their gig in Cardiff

We were growing exponentially and all of a sudden we became this juggernaut touring the world while inside the band, there was this tornado of insanity so while the band was growing, from the inside it was also falling apart.

Zoltan Bathory, Guitarist
The band first formed in 2005 Credit: PA Images

Some of the band members, including frontman Ivan Moody, went to rehab - and came out the other side.

"It came to a head - it was highly publicised", Zoltan said.

"Two years ago, that was when we hit the wall and these guys went to rehab, got sober and ever since, they're very focused."

Watch the full interview:

"It was absolutely crazy that we hid it from the world - or most of it.

"But when Nikki Sixx from Motley Crue comes over to your dressing and goes, 'Guys, I did some crazy stuff in my life but you guys need to step on the brakes.'

Zoltan said their drinking got so bad, that people like Nikki Sixx from the band Motley Crue had to intervene Credit: PA Images

"Nikki Sixx gave us an intervention. We were on tour with his band, and he was like, just shaking his head, like, "Oh my God guys, this is insane. You have everything in the world. Your band is blowing up. This is the position everyone wants to be in. What the hell are you guys doing?'"

"It's a pretty common thing. It's easy. It's a lifestyle and it's like, 'Oh you're a rockstar, you have to throw a TV out of the hotel room'. And everyone kind of falls into the same stuff, it just happens."

The band members got sober and Zoltan said it is because of their renewed focus, that things felt different this time.

The long-awaited eighth studio album, F8, is described as representing "rebirth and progression."

"We had an extremely successful, yet tumultuous couple of years as a band", Zoltan said.

"We didn't just weather the storm but came out on the other side better than ever. It was a focused sober group recording, our most important album to date and without a question it shows."

The band have played sell out gigs around the world Credit: PA Images

"Anger is a useful emotion - as long as you control it.

"If you look around in the world, especially today man, there's plenty of things to be angry about.

"You can in an environment - you can use that energy and that's kind of what we do.

The band has built a connection with their listeners through not just their sound but in their music videos.

Their songs are about war, the military, and their video for "Wrong Side of Heaven" is based on veterans suffering with PTSD and other mental health issues.

They actively support charities and set up 5fdpforvets.com to help raise money for veterans.

"I was born in a military base which means I was exposed to that from the get go", Zoltan said, who grew up in communist Hungary.

"I was in a political system I did not agree with."

"But I still recognised that these first responders, police officers sign up for a job. These guys put on their uniform in the morning and say goodbye to their families because it's not for sure they are going to come home".

The band has raised thousands for veterans' charities Credit: PA Images

Zoltan said he feels strongly about the emergency services and their role in society which comes across in their music, but has argued in the past, 5FDP are not a political band, but entertainers.

"So when we can make a statement and use our platform for various situations - we've raised a lot of money for veterans suffering with PTSD. I can say 'OK - check', I did something that mattered".

He sits on the board of directors of a charity which tackles elephant and rhino poaching in Africa and the band actively recruit veterans to their crew.

"It is an integral part of the band. To me its a passion. I like to do this stuff."

The album 'F8' will be released globally on February 28th, 2020 and is available to pre-order now.