"It's over! Completely over! What should I do?"
Liu Qiang, in a state of despair, got up and looked at his own hands, finding them empty.
Whether raising little ghosts or fiends, the principle is similar: using a secret technique to forcibly create something that doesn't belong in the mortal world, then forming a bond through a pact.
The master feeds the fiend; the fiend obeys commands and, after killing someone and absorbing energy, returns a portion of it to the master through the bond.
There's only one possibility for the bond to disappear — the two parties no longer maintain a mutual benefactor relationship.
In other words, the fiend you once raised will no longer follow your commands.
If the agreement to break the bond is mutual, letting it go to dust as it should, both sides go their separate ways peacefully. But if the bond is forcibly severed, the fiend, having been oppressed, will certainly seize the opportunity for revenge!