Background: Refused (also known as The Refused) is a Swedish punk rock band originating from Umea and formed in 1991. Refused is composed of vocalist Dennis Lyxzen, guitarist Kristofer Steen, drummer David Sandstrom, and bassist Magnus Flagge. Guitarist Jon Brannstrom was a member from 1994, through reunions, until he was fired in late-2014. Their lyrics are often of a non-conformist and politically far-left nature.
Context: Refused started as a "fresh-faced positive hardcore band" and their music became increasingly progressive and radical, as did their lyrics. The record This Just Might Be the Truth was characterized for its "massive hardcore sound", mostly influenced by various bands from the New York hardcore scene (such as Earth Crisis). On its follow-up, Songs to Fan the Flames of Discontent, the band had a heavier, more intricate style, which is generally attributed to their Slayer inspiration, and Lyxzen adopted screaming vocals rather than shouting. With the third album, The Shape of Punk to Come, "came the leap into the unknown" as the band mixed their previous style with unorthodox chord progressions, sampling, "ambient textures, jazz breakdowns", electronica and monologues, and other deviations from the hardcore punk music.  Refused's lyrics soon began to focus on far-left politics, drawing on anarchism, socialism, among others ideologies. By the time of their first album, the band already had a strong anti-establishment profile. The group's members were all vegan straight edge until their last show in 1998 and a couple of their songs dealt with these topics. Today, some of them no longer follow these lifestyles. In their live performances, vocalist Lyxzen usually delivers political speeches between songs. Before the Umea hardcore phenomenon went into full bloom, the band was seen as part of the scene centered around youth-oriented venue Galaxen, along with the punk-rock scene as well as metal bands such as Meshuggah.  Among the biggest influences of Refused were ManLiftingBanner, Born Against, Slayer, and Ian Svenonius's projects (The Make-Up, The Nation of Ulysses and Cupid Car Club). Other bands that have influenced them are Fugazi, Inside Out, and Snapcase.
Question: Who did the influence?

Answer:
their Slayer inspiration, and Lyxzen adopted screaming vocals rather than shouting.