Here’s what the Goetia says about Gusion:A great and strong Duke… He appeareth like a Xenopilus. He telleth all things, Past, Present, and to Come, and showeth the meaning and resolution of all questions thou mayest ask. He conciliateth and reconcileth friendships, and giveth Honour and Dignity unto any. He ruleth over 40 Legions of Spirits. His Seal is this, the which wear thou as aforesaid.
Now that sounds like a handy dude to have around for a soulless monster who would like nothing better than to drag you to Hell to suffer with the rest of the Damned.
I get the part about knowing the past, present, and future. And knowing the answer to all the questions you might ask. Honor and dignity are handy. So are friends.
But what the heck is a “Xenopilus”?
A little research turned up Xenophilius, which is the Greek term for someone who loves all things foreign (I can dig it.) and a character in Harry Potter. Somehow I didn’t think that was the answer.
Finally, a winding path led me to the possibility that it’s a mistranslation of “Cynocephalus.” As in a creature with the head of a dog.