Final Submission
Untapped/Unleashed
I want you to envision this example. Ginny Weasley gets her hands on an unassuming, blank book. She does not suspect the power lying in dormancy, untapped, in this item. Which, by the way, is incredibly durable and resists pretty much any attempt at destructing or harming it (Endurance). Now, when she dips her quill into the inkpot and starts writing... (Vile Vial). A terrible force is summoned, unleashed. A power that starts to wreak havoc and seems irresistible (Tinted Lens).
This works equally well with Light Yagami and the Death Note. Or Evy O'Connell and the Book of Dead. Or Charles Dexter Ward and the notebook of his ancestor Joseph Curwen.