Kyūsaku Yumeno

Yumeno Kyusaku (夢野 久作,) is a member of the Port Mafia. His ability is Dogra Magra.

Ability
His ability, Dogra Magra (ドグラ・マグラ,), curses his targets or 'Receivers' by ravaging their consciousness with hallucinations, causing them to attack everyone in sight with no regard on whom they might be; allies or foes, friends or enemies.

This curse is triggered by mutilating a doll that he constantly carries, which is the source. Receivers manifest marks on their body resembling a blotch. However, his skill also may rely on skin contact (similar to Dazai's), because the condition for triggering the effects is to "harm Q first", such as bumping into him or directly striking him.

Background
Because of the horrid nature of his ability, and demented state of mind of Kyusaku, he was locked up after many great sacrifices.

However, Ougai set him free in the middle of the war.