We have this name mentioned in 2 posts, if you used the search by typing in just the name:
This first guy is talking about the Book Lucifer and the Hidden Demons… so you might want to buy that.
I only found one online mention which was a " LAGIROS - Servo de ASTAROTH e ASMODI" yt video in Portuguese.
The text below this video also says he’s from the book:
To understand how to accomplish this pathworking, please read Lucifer and the Hidden Demons - A Grimoire of the Art of Faces Revealed, by Theodore Rose.
Yeah… you’re going to need that book. The first topic about him above says the same thing, follow the instructions in the book.
I have this book and the power in it for Lagiros is “To fill someone with uncontrollable anger”. Which is different than the 2nd link above.