The best I can share is an incident from our Pathfinder Game...
The Party:
Othar Deltrothus, Gentleman Explorer - Half-Elf Gear Head from Pure Steam
Shantara Swiftstaff - Half-Elf Bard/Fighter that will be taking the Dervish Presitige Class
Veleda the Huntress - Human Ranger with a Monkey named Spanky as an animal companion
Belanon, Scourge of the Undead - Cleric of Pelor
The PC's had been sent to look for a Precursor Artifact to help kill a Vampire who was trying to become a God. The person sending them was a Demonic Oracle. Their search took them to a Hobgoblin Crypt to find the remains of a Hob Archaeologist who specialized in Precursor MagiTech so they could find said Artifact. There they found and killed a strangely powered-up Gelatinous Cube. Inside the cube they found a small glowing orb.
I explained to the players that the orb is a fragment of a Demon Soul, typically created when a Demon is not powerful enough to resist having a piece of it soul sheered off. Basically a Long-Term investment, as the Soul-Shard grants control over the Demon much like knowing its True Name.
When they holed up for the night, they heard a whisper coming from the Orb. It was the Demon Oracle.
"It's about time, I thought you'd never find my Soul Shard."
Othar: "I thought we were looking for the Sun Stone?"
"You forgot rule number one. Demons Lie, Dumb-a$$."
Othar: "I'm really starting to like her."
Me: "Is that because I'm role-playing her the way I think you act?"
Othar's Player: "And you are doing a wonderful job!"