You must kill monsters from each level of the Stronghold of Security. The following monsters drop each piece of the sceptre:
- Minotaur - Right skull half
- Flesh Crawler - Bottom of sceptre
- Catablepons - Top of sceptre
- Ankous - Left skull half
Use the top and bottom of the sceptre on each other to form a Runed sceptre. Use the left and right halves of the skull to form a Strange skull. Finally, use the Runed sceptre on the Strange skull to form the Skull sceptre.
You may only have one Skull sceptre at a time, though you can keep any number of the individual components.