Shiku Shiku no Mi

Command over sickness is what this Paramecia grants its user, its name taken from shikku, the Japanese way of saying the English word sick. Doc Q, the ailing doctor of Blackbeard's fleet, is the one who carries it, having picked the power up through his crew's practice of stripping fruits from others. The ability suits him as a plague-bringer, a role sharpened by his skeletal steed and scythe, an echo of Pestilence from the Four Horsemen.

Whoever eats the fruit can conjure illnesses that come in countless shapes and degrees of severity, one such example flipping men into women. These maladies pass from target to target like a genuine contagion and cover a broad range, clinging even to a submarine as it dives deep beneath the sea. The user also senses the instant their power meets resistance. A strong enough burst of Haki lets a victim break the imposed sickness, and shaking it off spawns antibodies that spread just as fast, healing everyone else who was afflicted. Apart from that escape route, the standard Devil Fruit weaknesses still hold.

Doc Q stands as the sole known user. He briefly saddled the Heart Pirates with a Feminization Disease that turned every male crewmate of Law's into a woman. He came by the ability during or following the two-year timeskip, a product of the Blackbeard Pirates hunting down Devil Fruits. Standing as its exact inverse is the Chiyu Chiyu no Mi, a fruit that mends targets rather than infecting them, while the gender-swap effect mirrors Ivankov's Emporio Onna Hormone drawn from the Horu Horu no Mi.