Orb of Thesulah
About
In all seriousness, the Orb of Thesulah has been mentioned firstly in the Buffy the Vampire Slayer TV series. Then, it carried over into Buffy's spin-off, Angel. It was also referred to with loving affection by Sam and Dean Winchester in the series Supernatural. At this point, it is an inside joke. If you know, you know. #IYKYK
The joke is this - An Orb of Thesulah is a soul receptacle. It is a crystal ball used to summon and contain a human soul. In Buffy, it was used by a gypsy witch to curse the vampire, Angel, with the human soul he once lost. It pulled his soul from the great beyond and contained it until it could be transferred back into his undead body. However, the translation for the ritual described above (aka The Ritual of Restoration) was lost. Meaning, the Orb of Thesulah itself is completely useless. All it is good for is a new-age, fragile paperweight. Watch Buffy for more details.
The mention of the Orb of Thesulah is my way of blowing a gentle kiss to Buffy for the way it shaped not just me, but most importantly the world. I blow a few other kisses in The Netherworlds too. There are kisses to Edgar Alan Poe, Doctor Who, Paradise Lost, Alice in Wonderland, Arabian Nights, etc. And I suppose these can be used as keys to the world building of the Netherworlds and how realities and magick work in the story, but I'll leave that to greater minds than myself to figure out.