Ganno

The novel puts him in his mid-sixties, crimson-haired, his thin arms darkened by sun. The red paint coating his fingernails marks him out even at a glance. The manga and anime instead give him long white hair and fair skin.

Painting is less a hobby for Ganno than a compulsion. He is rarely parted from a brush and shows scant interest in anything else, an obsession inherited from his painter father. That fixation once curdled into scheming, yet he is also quietly perceptive: over a shared meal he notices Sakura's wedding ring and, from little more than her hair color and a courtyard tree, deduces that her husband is his cellmate Sasuke.

Ganno built a reputation in Redaku's capital painting portraits of nobles, until it emerged he was using those commissions to turn rival nobles against one another. Convicted of state treason, he drew a seventeen-year sentence at the Astronomy Research Institute. Prison did not stop him: he gathered reddish stones from the quarry work, ground them to powder, and boiled the dust with skin peeled from his own foot to make a red paint, applying it to his nails with pine-needle brushes and completing roughly a project a week even though the guards always confiscated his tools. During Sasuke Retsuden he shares a cell with Penjira, Jiji, and Sasuke, declining their dice games to keep painting. When reincarnated dragons tear through the prison, a feathered beast hunts him down and nearly crushes him, only for the creature Menō, now on Sasuke's side, to intervene and buy him an escape. He and Penjira then pin a downed dragon, hammering its knees to keep its wounds from healing, a tactic other prisoners copy until Sasuke and Sakura banish the dragons for good.