Ryūnosuke Akutagawa vs. Masked Assassin

Ryūnosuke Akutagawa vs. the masked assassin is a battle fought between Port Mafia member Ryūnosuke Akutagawa and a masked assassin who turns out to be the former Guild operative Nathaniel Hawthorne.

It happened along a back alley during the wake of recent attacks on ability users by the masked assassin. The event is part of the Cannibalism strategy instigated by Fyodor Dostoevsky and the Rats in the House of the Dead in Yokohama, which is later revealed to be part of a bigger plot of the terrorist association, the Decay of the Angel.

Prologue
Sometime after the three-way gifted organizational conflict, a number of nighttime attacks on ability users have been reported. The assassin has also been sighted as a masked assailant using an unidentified ability.

Armed Detective Agency president Yukichi Fukuzawa soon falls prey to the masked assassin's attack and becomes afflicted with strange symptoms. During this time, in line with their duty as the "Wardens of the Night", the Port Mafia begins hunting the assassin throughout Yokohama, more so because of the apparent humiliation and offense it brings them due to the assassinations occurring right under their turf.

Mafia boss Ōgai Mori dispatches the Black Lizard after they locate the attacker's hideout, only to find it empty. As a secondary measure, Mori anticipates an attack on his life – later proven true after an explosion is triggered on his car – and has Akutagawa track down the signal from the remote that triggered the explosion. He traces the signal to a back alley, where he finds a puddle of blood and the masked assassin himself.

Akutagawa confronts the assassin, who claims to be carrying out the assassinations for the sake of reviving his beloved. The mafioso does not acknowledge his goal to be a bad cause and challenges the assassin to prove himself.

Battle
Akutagawa summons various spikes of Rashomon through the walls and ground and instantly punctures the assassin's body. However, the latter is able to dodge the attack and leaps through the air. Akutagawa nonetheless manages to break his mask, revealing him to be Hawthorne. He also realizes how his ability allows him to walk mid-air by stepping on the red letters, after which Hawthorne's blood bullets shoot towards Akutagawa, who quickly puts up his defense.

Akutagawa then infers that the puddle of blood at the alley becomes his primary source of weapon to convert them into his unaided attacks. He expresses his disbelief in how a devout man such as Hawthorne has resorted to quite a devious scheme. Recalling the assassin's earlier motive, Akutagawa asks whether he has been referring to Margaret as his "beloved", but Hawthorne blankly stares and shows no memory towards Akutagawa.

Aftermath
Sometime after the encounter, Hawthorne presumably stops his attacks on ability users but resurfaces later on, possibly since Mori has then been inflicted with the Cannibalism virus like Fukuzawa, which is the primary motive of the plot's mastermind, Fyodor. With the said virus putting Fukuzawa and Mori on the literal brink of death if one does not kill the other, Akutagawa later regroups with the Mafia to actuate a feud against the Agency in an attempt to save their boss's life.