In the standard Rider-Waite, the 8 of Cups is about walking away. In the Goetia Tarot, the 8 of Cups may feature the Sigil of or Gaap . The PDF guidebook provides a direct cross-reference: which demon rules which card's specific energy. Without it, you are performing cold readings.
As of this writing, Lo Scarabeo (the publisher) has not released an official stand-alone digital version of the Goetia Tarot in Darkness Guidebook due to licensing agreements with the artist. goetia tarot in darkness guidebook pdf top
The Goetia deals with potent, often challenging energies. Always approach the deck with respect and a clear intention. In the standard Rider-Waite, the 8 of Cups