secret identity, Gyro has invented the Caramelle cancelline (or Car-can in short, meaning "erasing sweets"), pills which causes complete loss of memory of the most recent few hours upon ingestion: after every meeting with Paperinik, Gyro takes one of these pills as a safety precaution. They are called UhKa, short for unohda kaikki in Finnish or VergAll, short for vergiss alles in German, both meaning "forget everything". Later stories, however, disregard this particular detail. PK The character was renewed in PK - Paperinik New Adventures (often shortened as PKNA), a series of comics published in Italy between 1996 and 2000 in which the character of Paperinik, here often called "PK" for short, is revolutionised and featuring stories with more mature tones and dedicated story arcs. In this issue, after Gyro "resigned" from being Paperinik's armourer (as shown in a special issue), Donald finds himself aided and geared up by "Uno", an extremely advanced AI, into dealing with new threats coming from space or from the future: distinctive weapon from this series is the Extransformer Shield, an all-purpose advanced robotic gauntlet. The series was science fiction and while previously-existing Disney characters were rarely seen, it introduced its own universe of characters like PK's allies, such as the gynoid time-policewoman Lyla Lay or the alien Xadhoom; recurring antagonists were the evil "Evroniani" aliens and time criminals such as the "Razziatore" (Red Raider in the US). After closing the various arcs introduced with the series, it ended with the impending return of Everett Ducklair, Uno's creator. The series was followed by a sequel named PK² (2001-2002), which started directly from where PKNA ended, with the return of Everett Ducklair to Duckburg. PK² was considerably shorter than PKNA and the story arcs revolved mostly around Ducklair's ambitions and the consequences of his past mistakes. After Ducklair shuts down Uno and forbids PK to use his inventions as well as his tower at the very beginning of the series, it keeps its core not only on PK as a superhero but also on Donald as a citizen and person, introducing more mature topics linked to the everyday life (also in relation to PK's struggles as a hero) and more realistic interactions between characters. After PK², a reboot named PK - Pikappa (2002-2005) was published. This series aimed to rewrite and revamp Paperinik/PK's origins by keeping some few core elements from PKNA: as a matter of