When Problem Sleuth uses Sepulchritude, the true form of the ink is revealed - it is the innocuous double of Tectrixcalibur's scabbard. Sheathing the blade covers it in ink, making it similar in use to ammunition due to the ink "meter" shown while Sepulchritude is active. Since it is a pun off of the phrase Quid Pro Quo, which means that one receives something for doing something in return, it may or may not be applied in that manner. It is also rather ironic in that Problem Sleuth obtained the ink with no effort, it having merely fallen next to him.