Dogra Magra is a mind control ability, described by Osamu Dazai to be the anathema of all abilities and the ultimate reason why Q was sealed in confinement by the Port Mafia. To activate their ability, a target or "receiver" hurts Q through several means; notably, Q employs tactics to trigger getting harmed, which they shall use later to their advantage by deliberately hurting themself through another person as their medium. For example, they bumped themself on Atsushi Nakajima to cause razor blades taped to their arm to hurt them, and they also once intentionally pushed their own hand wrapped in thorns onto Howard Phillips Lovecraft to curse him. A handprint blotch appears on the receiver's body to signal they have been cursed, and Q's doll apparently laughs maniacally. Q then mutilates their doll, and the receiver is ravaged by sinister illusions, which makes the target attack everyone within proximity in a blind rampage. Notably, receivers unconsciously cry tears of blood when cursed.
Apparently, once activated, Dogra Magra is inexorable and cannot be terminated at will. Thus far, the only method to cancel the ability is through Dazai's No Longer Human. However, Q can always reactivate their ability whenever they wish to even after nullifying it. Nonetheless, the ability's fatal effect may be counteracted by tightly securing the receiver once a handprint blotch appears on them. For instance, Doppo Kunikida was heavily restrained upon noticing that he had been imprinted with Q's handprint. Hence, he was unable to harm anyone in a possible rampage during the curse and until it was lifted.
Dogra Magra may work on a number of receivers simultaneously, especially when activated in conjunction with a sensory-linking ability such as John Steinbeck's grapevines. During the emergency plan executed by the Guild, Q was restrained to Steinbeck's grapevines that were linked to all of Yokohama's trees. By stomping all over the trees' roots and chopping off their branches, the pain being signaled on the trees were transmitted directly to Q, which therefore harmed them and established the initiative condition for Dogra Magra. Q then activated their ability, and about one-fifth of Yokohama's citizens were cursed. Later, Francis Scott Key Fitzgerald rips off the doll's head, causing the cursed citizens to go on a rampage throughout the town. Dazai eventually touches the doll through Atsushi's efforts and ends the curse.
The ability is named after the real-life Kyūsaku Yumeno's 1935 novel Dogra Magra (ドグラ・マグラ, Dogura Magura?), alternatively entitled Encephalon Hell (腦髓地獄, Nǎosuǐ Dìyù) in its Chinese translation. The novel opens with the narrator known only as the ambiguous "I" (私, Watashi?) waking up in an asylum with amnesia. Upon learning that he was the subject for a psychiatric experiment known as the "madman liberation therapy" developed by a now-dead psychiatrist, he soon struggles in a psychological spider's web interwoven by the institution's faculty in search of his identity and his possible connection with a mysterious crime.