The Netherworld Fire Fireflies that appeared on Shen Siyuan's hand seemed to feel the vibrations, one by one awakening, then vibrating their wings and flying into the air, scattering around.
The humming sound of the vibrating wings was incessant.
But soon, it was accompanied by the "whoosh whoosh" sound of cutting through the air.
These finger-sized Netherworld Fire Fireflies, like sharp swords piercing the void, flew around Shen Siyuan's body, up and down.
Some landed on his shoulder, some on the lapels of his garment, and some even on his head...
Shen Siyuan felt immensely grateful that the Jiuyou Demon Lord had used the Ten Thousand Soul Banner to refine and cultivate these Iron-eating Fireflies.
Otherwise, he would not be able to control these Netherworld Fire Fireflies as if they were extensions of his arms, and he might even have been devoured by them.
However, the number of these Netherworld Fire Fireflies had indeed decreased, Shen Siyuan counted only seventy-nine.