Ango Sakaguchi

Ango Sakaguchi (坂口 安吾,) is a government worker whose ability is Theory of Corruption.

Ability
Theory of Corruption (堕落論,)

Trivia

 * In real life, he is often grouped together along with Dazai Osamu and Oda Sakunosuke as the Buraiha or Decadent School. 
 * And on the series, this is often alluded, because the three used to meet in a certain bar, as seen in Dazai and the Dark Era, and illustrated on the calendar.