Emperor and most magnificent ruler of all spirits
There is astonishingly little known about this spirit, which may be one of those Book of Oberon originals that just didn’t catch on. However, his role in Oberon is pretty amazing: Near the top of hell’s hierarchy there are three well-known spirits who have all been kings of hell in their own right: Lucifer, Beelzebub, and Satan. There’s also the four kings of the directions (Paimon and the like). It is very difficult to control these three, unless you call on Tantavalerion, the “emperor of all hellish spirits.”
Who is he? No clue. He’s mentioned in two sources, according to Bellanger, and one of them is Oberon which has a lot of whimsical editions to the demonic lists. In both of htese sources he’s extremely high up, also serving on a short list of the senators of hell (along with Orymell, Tygra, Danall, Saalarica, PAscary, Buell, and Asmoo.)
His name is mentioned in parallel with Lucifer’s name, suggesting that he might be some sort of alter-ego representing Lucifer’s control over hell. His other name, “Golgathell,” suggests that he’s possibly some kind of angel associated with Golgatha, where Jesus died on the cross and presumably descended into Hell, so that suggests the possibility that he’s some kind of angel of death, or somehow associated with Jesus’s death.
For a really esoteric theory that we haven’t seen elsewhere, “Golgatha” is “the skull,” could it be that Golgathell and Tantavalerion (the word roughly means “equal in strength” or “of great force) are the power of the mind? That seems reductionist and “wizard of Oz,” we’re just throwing it out there. Or, as the ultimate angel of death, including a death of God (he got better), he may be something like the animating spirit of the underworld itself, and in this sense, Lucifer’s landlord.
Anyway, this spirit is rarely mentioned and amazingly powerful, which perhaps says more about Oberon and its outsider status as a grimoire as much as the entity itself.