Conversation so far:
What record label were they with?
Def Jam Records, a largely hip hop-based label.
Did they play hip-hop?
ditched in favor of stripped down, hardcore punk influenced song structures.
When did Reign in Blood come out?
The album was distributed by Geffen Records on October 7, 1986.

Question: How was it received?
Self-contained rewrite: How was Reign in Blood by Slayer received?