Between the major star domains, there are corresponding laws of balance.
Even when Shen Rufeng once used the Shen Family's influence to leave behind laws in the Black Water Star Realm, he had not yet reached Nascent Soul Divinity Transformation.
If he becomes a Divinity Transformation expert, unless he is a life form born in the Black Water Star Realm, under the law of balance, he simply cannot enter.
Therefore, the most effective and straightforward way to kill Ling Feng is through spiritual will descent. Spiritual will is an emotional thought, much weaker than divine soul power.
But Shen Rufeng's physical body is one with the stars, cultivated alongside the sun and moon, making him the supreme Integration Cultivator, about to face the trial of thunder tribulation. Even just a spiritual will is not something beings like Qiankun Zi can resist.
