"The term “Prince of the Church” regarding cardinals is a historical reference to those who held the equivalent role of a royal prince and in a feudal times ruled a principality."
http://catholicnewsherald.com/faith/101-news/faith/2864-cardinals-of-the-church
And then there's this:
https://en.wikipedia.org/wiki/Classification_of_demons#The_Satanic_Bible