Liu Bang took a gulp of wine and went on talking.
The thirty-six tiers of Heaven Immortal realm could be divided into four grades, one for every nine tiers—the lower grade, the middle grade, the upper grade, and the top grade. A standard planet, which had a standard number of energy veins, a standard level of natural energy, and a standard size, could provide enough resources for three to five lower-grade Heaven Immortals. But, a middle-grade Heaven Immortal needed all the energy and resources of a standard planet to grow his cultivation base at a steady pace.
