So, to put it simply, this little thing is a listening device + sound amplifier of this world, and it can move around freely and is hard to detect! It's simply the best espionage agent.
In contrast, the same is true for this man himself. In many situations, both cultivators and demons cannot see mortals. But mortals are the largest population group in this world; they are as inconsequential as grass and ants, spilling invisibly upon the earth, aren't they also invisible spies?
This man's identity is that of an "Insect Servant." His task is to nourish this echo worm with his own essence, and then, at the right time, release it to gather all kinds of gossip and information. Miluo has somehow managed to breed the echo worms on a large scale, and it is unknown how many "Insect Servants" he has planted as his informants across this vast land.
