The Seven Satans, also know as the Seven Sins or Seven Deadly Sins, are the seven angels (eight, if you consider Astaroth and Astarte as two separate people) that followed Lucifer in his fall from Heaven. They each represent a sin.
“The Seven Satan of "Envy". He was once an angel who sheds his angel-hood and dons the cloth of a...Leviathan
“One of the Seven Satans, Lord of Flies, "Gluttony", formerly a member of the Seraphim. He is not...Beelzebub