Strange Changes in the Spirit Insects

Dong, dong, dong!!

The mysterious person struck the strange drum, producing a weird and rhythmic sound. 

The sound was incredibly faint, even quieter than the sound of a mosquito in flight, barely noticeable, and almost imperceptible. If anyone were present, they would undoubtedly find it very eerie. The sound of the drum was so soft that it might not even reach three meters away.

Why was the mysterious person doing this? The sound couldn't even reach beyond three meters. No matter how remarkable this strange drum was or how intimidating it could be, it seemed futile.

Nonetheless, the mysterious person ignored this and continued to beat the peculiar drum. While doing so, he mumbled something under his breath, as if reciting some particularly strange incantation.

With the combination of this drumming and the incantation, a strange ripple spread rapidly in all directions with him at its center.