Arakune

アラクネ

A black, blob-like creature wearing a white mask, who previously worked with Kokonoe, Tager, and Litchi in Sector Seven. He was formerly a human named "Lotte Carmine." After attempting to study the Boundary, driven by an inferiority complex regarding Kokonoe's genius, he transformed into his current state. His body now houses countless insects, and he thrives on knowledge. His horrific condition has left him virtually insane and devoid of reliable memory, while also distorting his speech to near incoherence—most of his dialogue consists of gibberish, insane laughter, and tortured screaming. (However, it appears that only Litchi understands his words.)
His dialogue with various characters, along with his Arcade Mode ending, suggests that the power and knowledge he gained from the Boundary gradually turned him into what he is. Notably, according to his Arcade Mode ending, he does not seem to have noticed his transformation; to him, his bizarre speech is completely normal. He appears not to understand why others cannot comprehend him, creating a crude mask for himself in the belief that it would help others understand what he is saying.
During Calamity Trigger, he resides in the sewers of Kagutsuchi, where the seithr concentration is highest, and attacks anyone who visits. He is also known to attack and devour his victims to sustain himself, specifically targeting the Kaka clan, the closest living creatures. He thirsts for power and knowledge above all else, considering the Azure Grimoire the pinnacle of such. Whenever he encounters Ragna, he becomes obsessive in his desire to consume the Azure, often saying only "AzureAzureAzureAzure" in Ragna's presence.
In Continuum Shift, Arakune continues his search for the Azure Grimoire. He is also shown to be capable of speaking like a normal human, though only temporarily before slipping back into insanity. During this brief period of sanity, he told Litchi to stop her attempts to cure him using the same power that drove him mad, and instead to seek healing from Kokonoe; there is a fine line she should not cross, or she could end up like him. A later encounter with Terumi reveals that Arakune was used as an experiment to create the Black Beast, but he ended up as a failure, knowing only how to consume others.
He seems to remember Relius Clover and harbors a deep hatred for him. Their initial encounter is revealed in Continuum Shift II's 2nd Extra Story - "That Which is Inherited." Unfortunately, during one of his encounters with Relius, he is struck down and subdued by Relius' own marionette, Ignis, and taken into custody. Terumi later uses information about his captivity to eventually push Litchi to join the NOL.