That bundle of stuff seemed to be frightened by something. It flew out as if it was seized with panic. When that bundle rolled out back and forth, people jumped in fright!
The reason was that the bundle had a face. The face was somewhat similar to that of the Nascent Soul Old Monster, except that his face was wrinkled and old and the things that rolled out was like a newborn. It looked like a miniature version of the Nascent Soul Old Monster complete with feet and hands, but the body was only slightly bigger than the fist, and the whole body was smooth and slippery, being protected by the spirit energy. It used its limbs to throw itself forward in order to escape.
"That's his Nascent Soul!"