It took more than a day to absorb a Dragon's Mana Heart. Each Dragon Heart held about a thousand years' worth of energy. Considering the immense amount of energy Mu-Gun absorbed, one day seemed like a surprisingly short period.0

Absorbing the energy from the Dragon Heart granted Mu-Gun ten gapjas worth of power. Although it accounted for roughly sixty percent of the total energy stored in one Dragon Heart, this achievement alone was truly remarkable.0

Truth be told, a Drake or a Wyvern's Mana Heart held more than ten gapjas of energy. However, after extracting the demonic essence and purifying it with the Thunder God Qi, only two gapjas worth of energy would remain.0

On the flip side, he managed to absorb around sixty percent of the Dragon Heart's energy—three times more than that of a Drake or Wyvern's Mana Heart. This served as evidence that a Dragon Heart's energy was pure and high-dimensional. Even after absorbing the Dragon Hearts' energy, Mu-Gun continued to circulate his qi without taking a break.0

He ceased circulating his qi only after fully integrating the Dragon Heart's energy as his own. Through absorbing the Dragon Heart, Mu-Gun's Thunder God Qi swiftly surpassed forty gapjas. Even though his internal energy surpassed human limits, it still fell short of summoning all four Spirit Kings simultaneously.0

To summon all four Spirit Kings, he needed to absorb at least one more Dragon Heart. Yet, absorbing another Dragon Heart immediately posed a challenge. Although he completely assimilated the first...0