abode of demons; hotbed (of graft); pandemonium
その省庁は伏魔殿と揶揄されていた。
That government ministry was mocked as a den of demons.
伏魔殿と化した組織の改革に着手した。
They set about reforming the organization that had become a hotbed of corruption.
かつての伏魔殿が浄化され信頼を取り戻した。
The former den of corruption was cleansed and regained trust.