Noah didn't fear for his life, but he didn't want to risk suffering such an insidious injury and possibly lose his fourth center of power. His healing abilities were off the scale, but the heart was too delicate to ignore the danger.
The Demonic Sword roared as it understood his intentions. The weapon was still in his grasp, so Noah only had to place it on his dantian to resume cultivating.
The black star in his heart had become unstable because his darkness's structure had changed when it reached the solid stage. The old harmony didn't work anymore.
The solid "Breath" was heavier and required a higher density to evolve. The only solution for the current situation was to pour more energy inside the dark star until it found new stability. However, Noah had just advanced, so his dantian was mostly empty. He had to cultivate before he could fill his burning heart.