A crystal.
It could be used for construction, Death Knight production, or any other time-consuming process.
Each crystal could save 10 hours of production time.
And if 300 crystals were collected, they could be used to draw artifacts like the Ring of Communication or the Crown of the Absolute.
"When was the last time I drew an artifact?"
Crystals were so rare that I never even got close to collecting 300—I always had to use them before reaching 100.
And right now, I had none at all.
Oh oh we’re fighting robots now, this is where that electric guy from the vampire saga would come in handy