Mustering all of his creative juices and honing his songwriting, he led Kreator into Los Angeles' Music Grinder Studios and brought in well-regarded producer Randy Burns (Megadeth, Nuclear Assault, etc.) to guide them to another thrash metal landmark with 1989's Extreme Aggression. With videos made for the ubiquitous title track and the venomous "Betrayer" getting plenty of exposure on MTV's Headbanger's Ball, Extreme Aggression quickly became their biggest seller yet, and the subsequent North American swing with Suicidal Tendencies introduced the band to many new friends. The tour also marked the debut of former Sodom guitarist Frank "Blackfire" Gosdzik, whose nightly lead guitar duels with Petrozza are still the stuff of fond memory for Kreator fans. Seeking to capitalize on the group's momentum, Noise rushed them back into the studio to whip up next effort, Coma of Souls, released in October 1990. Unfortunately, the hastily conceived L.P. clearly suffered from the less than favorable circumstances in which it was created, seeming too much like a retread of earlier material and bogged down by filler. It should also be noted that, by the end of the 1980s, thrash and speed metal had largely run their course and mutated into death metal, leaving genre standard-bearers like Kreator, Anthrax, and even Metallica, with a difficult choice: evolve or perish.1992's appropriately named Renewal seemed to answer that question by going straight to the source for help. Kreator sought out renowned producer Tom Morris (Sepultura, Morbid Angel, etc.) at his Morrissound Studios in Tampa to help them delve deeper into the death metal template. (One thing that needed no updating was Petrozza's hissing, scratchy voice, which of course predated, and no doubt influenced, death metal's Cookie Monster vocal style.) Proving just how wary (perhaps too wary) the studio was of current trends, Renewal also came slathered in industrial-metal techniques
?? something that did not go over well with Kreator and was later blamed for the album's disappointing showing. The excruciatingly taxing touring commitments that followed took the band as far as South America, but understandably left them physically and creatively exhausted, prompting Petrozza to announce a protracted break to recover. Incredibly, Kreator's silence was only broken three years later with the release of 1995's, somewhat back to basics, Cause for Conflict
?? their first effort for new label GUN Records. Hardly a successful comeback, the album found Kreator confused and uninspired
?? hopelessly out of touch with the day's reigning extreme metal trends, and surely traumatized by the recent departure of both Fioretti and Ventor (they were replaced by bassist Christian Giesler and former Whiplash drummer Joe Cangelosi). Adding insult to injury, Noise Records chose exactly this difficult moment to release the Scenarios of Violence set
?? a collection of live recordings and remixed old hits that seemed to declare Kreator's future prospects null and void.Looking to remedy the band's tenuous situation, Petrozza called upon former Coroner guitar wizard Tommy Vetterli to help him guide Kreator into realms unknown, getting even further away from their roots on their next two albums, the highly experimental Outcast (1997) and Endorama (1999). Both of these veered into ever-slower pacing, added gothic and ambient elements, incorporated samples and loops, and even found Petrozza trying a few different singing styles on for size. But even though they met with certain critical acclaim and signaled Ventor's welcome return to Kreator's ranks, neither of these albums managed to re-ignite the band's career. Yet again, timely retrospective releases like 1999's Voices of Transgression (shedding light on the band's hit-and-miss second decade) and 2000's Past Life Trauma (a near-flawless wrap-up of their first decade) provided some consolation for disgruntled old fans who had long abandoned Kreator's floundering ship; but, unexpectedly, they also cleared the way for a rebirth of sorts.This renaissance began to take shape following Vetterli's departure and the signing of a new record deal with Germany's SPV label. Simply put, Petrozza recommitted himself to thrash, and, after hiring Finnish-born second guitarist Sami Yli-Sirnio, proceeded to write Kreator's strongest album in years, with 2001's positively stunning Violent Revolution. In keeping with Kreator tradition, the consequent world tour became their most comprehensive and extensive ever. Thanks to Violent Revolution's great success, it served to reintroduce and reestablish Kreator as one of the world's premiere speed metal acts
?? a feat that was commemorated with the group's first live album
?? a lavish two-CD/DVD set appositely named (with some grammatical license) Live Kreation/Revisioned Glory
?? a couple of years later. Surely already preparing for their 11th studio album, Kreator will probably never retire.