"Demonification?"
"Demonification will occur when the container which is a human itself is no longer able to withstand the large amount of power it gets and slowly the human will be controlled by the devil and will turn into the devil itself."
"Am I going to change like that too?"
"Depends, if you hunt down contractors you will become strong and in return you will slowly not be able to withstand the power you have and turn into a demon instead."
"Isn't there a way to keep a contractor from turning into a demonic figure?"
"Never before has a human managed to withstand demonification as far as I know."