Usually metal tracks mashed up with non-metal songs are good for a laugh, or maybe even getting stuck in your head for a little bit. This one is genuinely pretty heavy. Backed by Slayer's "South Of Heaven," the vocals from Edwin Starr's 1970 hit "War" take on a whole new sinister feeling and somehow still retain a very evil Slayer vibe. I'm sure the lyrics help alongside some of Starr's raspier calls for war.
The mashup was created by Bill McClintock, who has given us such gems as Pantera combined with Bill Withers in the past.