People saying Ryuji's Bullshit Detector is useful but when has it ever not been useful?? Even though Ryuji said it was useless I've always thought it was one of the strongest Sigil I've seen. It could single-handedly change modern politics, criminal law, everything. Forget the power to insta kill people or mass murder. In any time, whether peace or crisis, a 100% accurate lie detector is absolutely legendary.
Ryuji is definitely up there with Kaname in terms of Sigil with crazy realistic uses.