With respect to policymakers in the nerve center of the Imperial Court between the 10th and 11th centuries, in particular, onmyoji played a significant role in various affairs, from politics and staffing to an Emperor's abdication from the throne, including being instrumental in the incident when Sadaijin (minister of the left) FUJIWARA no Tokihira demoted SUGAWARA no Michizane from a ministerial office to Dazai no gon no sochi (Shotai Incident).
特に、10世紀から11世紀における朝廷中枢の為政者に対しては、左大臣藤原時平が菅原道真を大臣職から太宰権帥に左遷した際（昌泰の変）に深く関与したことをはじめとして、政治運営や人事決定から天皇の譲位に至るまで多大な影響を及ぼした。