Complex sentence: They subsequently signed to Reprise Records and released "The Madness Begins" EP in 1988, a release distributed mainly via a promotional ad featured in some of the most popular metal magazines of the era.
Split into simpler sentences: They subsequently signed to Reprise Records and released "The Madness Begins..." in 1988. The release was mainly distributed via a promotional ad featured in some of the most popular metal magazines of the era.