The pain of his soul was beyond the physical pain, yet Ludwig's face didn't change at all, eve after having cut off a part of his soul that connected the body deeper with him, in normal circumstances, doing this might loosen the grip between the body and the soul, but at this moment, the heart which he was moving the whole time finally entered the dantian.
It was a weird sensation for Ludwig, but he didn't mind it. He felt carefully in his body and truly didn't see a second heart or even an illusory heart. Now that he moved the heart, the next issues would commence.
Naturally he needed to re-direct the veins and meridians of his body to his dantian, else his movement would become worse. The issue now was that with the movement of the heart, the veins to the brain would need to be stretched, while the veins to the legs needed to be shortened. It was a difficult situation and Ludwig had to play doctor.