Runes
From Astrolords
Rune is an essence of an unknown nature that possesses amazing properties, which has been created by the Forerunners.
After its properties have been unleashed, the Rune crumbles in a short period of time, which depends on particular Rune and varies from 2 to 4 days.
Players can find Runes in the Obelisks of Forerunners of the Oort Cloud or purchase them at the Store; Improvements tab.