Here are the last words of a famous Satanist. "What have I done, there is something very wrong" - Anton LaVey (1930-1997)
Here's a video detail his final moments just before his death. He was the Founder of the First Church of Satan, and author of The Satanic Bible. In his final moments, Anton comes to the terrible realization that he had allowed himself to be deceived by the devil and now faces eternity in hell.
It is certain that Anton Lavey went to hell if he did not receive salvation on God's terms before his demise. This requires repentance, belief and baptism.
"Depart from me, ye cursed, into everlasting fire, prepared for the devil and his angels" - Jesus Christ
Proverbs 14:12 There is a way which seemeth right unto a man, but the end thereof are the ways of death. Someone once said: "I'd rather die believing and find there was nothing, then believe there was nothing, die and find out otherwise." I say that God gives ample evidence of his existence now (by his Holy Spirit) and that only the fool says in his heart that there's no God. In the end, we all will see for ourselves.