The cultivation level is the fundamental strength of a practitioner and encompasses divine skills, destiny, mana, and more. The stronger the cultivation level, the more powerful the divine skills and destiny become, and naturally, the mana is even more formidable.
In the Jiawu Realm, once a practitioner's cultivation prowess breaks through the hundred-year limit, it essentially becomes a reduced version of the cultivation level.
In the early stages, this is not apparent and accumulates easily. As one enters the middle and later stages, the difficulty of increasing this cultivation prowess becomes increasingly evident. Without relying on malevolent ghosts to carry the lotus, Tan Shuchang would have found it impossible to accumulate a thousand years of cultivation prowess.