Adding Lu Xiaotian's own, more than thirty streams of dan qi of varying strengths crisscrossed the area. Under normal circumstances, these thirty-three Dragon clan Dan Saints could more or less control the fluctuations produced by their alchemy, so it wouldn't have been much of a problem. But in this area, barely a thousand li across, so many streams of dan qi of varying strengths were interfering with and assailing one another. Under these external influences, the Dan Saints could hardly keep them in check.
Dozens of streams of dan qi had been produced by Second- and Third-Grade Dan Saints. The turmoil they caused had already far surpassed the disturbances created by two or three Celestial Immortals fighting.
Lu Xiaotian was no stranger to this situation. He had already experienced the conflicts caused by different Dan Saints refining pills back in Nine Central City, when he had refined the Golden Towers Nine Extremes Origin Transformation Pill for Xue Daoyuan. At the time, he had needed to harmonize nine different streams of dan qi and prevent them from clashing too violently. It was then that Lu Xiaotian had grasped the realm of using heaven and earth as a furnace.
Now that he had advanced to Fourth-Grade Dan Saint, he was naturally even more familiar with this realm. Although he had grasped it and could make use of it to some extent, using heaven and earth as a furnace still had its flaws. Ordinary Dan Saints were still safer refining pills in a pill furnace. When the medicinal power of certain immortal plants and materials clashed too violently, using heaven and earth as a furnace made it all too easy for it to leak out.
Even so, whether one could reach this realm was extremely important. If one could, then even if some