Every demon is a unique being. No matter how servile, no matter how obedient, they are still capable of independent thought. This is frustrating. Since any demon is capable of growing immensely powerful, without proper attention, a useful demon often becomes a threat over any long period of time.
I have had too many instances of useful tools developing a bit too much personality.
So I have developed a solution. The power of a demon augmented through the demonic sciences. In some ways they are more limited, perhaps a bit more delicate, but certainly capable of outputting immense amounts of magica, and most importantly- incapable of disobedience.
The early prototypes have begun production. I am very eager to put them to the test...
-Notes underneath complex and arcane equations, in the lab of The Master