vassago is the third out of 72 demons listed in the "the lesser key of solom", which to my knowledge is a section in the first of five anonymously authored books this one named "Ars Goetia". vassago's gender is unclear to me cause some witches have led me to beleive they are a woman but the original text refers to him as a man so I will be doing so to. vassago's personality is extremely good natured despite being a fallen angel to the point that in "the book of office spirits" he's referred to as an angel names Ussago. vassago's abilities/powers consist of revealing hidden truths about the past present and future and finding things, both of his powers are extremely broad specifically finding things. finding things can range anywhere from helping you find a lost pen to helping you find your soulmate, either way its can be extremely useful.
I worship vassago like anyone else, with the intent of building our relationship enough for him to be willing to work with me, for currently he declines any job offer I give him. I chose vassago mostly because he was the first demon that caught my eye and I didnt wanna go through all 72 demons in Ars goetia when I'd probably just end up back with vassago, but thats not the only reason. I also chose vassago cause his abilities are very broad and that allows me to be very specific with what I want to achieve