Jiang Chen had plotted out everything before arriving. The Longevity Pill was a most wondrous pill, and the pill recipe Jiang Chen had produced back then was the most common one. In reality, there were a total of eight ways to make the Longevity Pill. The recipe he used during the Mt. Rippling Mirage Pill Battles was just one of the many pill recipes that existed, and he'd used it only because the ingredients he had been provided coincided with the ones in that particular recipe.
It definitely wasn't the only pill recipe that could create the Longevity Pill. Moreover, many of its ingredients could be replaced. He hadn't told even his Regal Pill Palace sect mates about this. After all, this particular version of the Longevity Pill was difficult enough to digest already. He doubted that a sect at the Regal Pill Palace's level could digest the rest of the pill recipes even if he were to reveal them.