Vassago

Vassago (also Vasago, Usagoo) is a demon described in demonological grimoires such as the Lesser Key of Solomon and the Book of the Office of Spirits.

[1] He rules twenty-six legions of spirits, and is summoned to tell magicians of past and future events, and locate lost objects.

He is one of the few spirits found in the Lesser Key of Solomon but not in Johann Weyer's Pseudomonarchia Daemonum.

Murderer and vampire-themed cult leader Rod Ferrell used "Vassago" as a "vampire name" and burned a V representing this alias onto his victims; Ferrell did not know how to spell or pronounce Vassago's name correctly, and typically called himself "Vesago".

[9] Vassago appears as a character in the animated web series Helluva Boss (voiced by Harvey Guillén), alongside some other Goetia demons like Paimon, Stolas and Andrealphus.