Hailing from the Cassandran Worlds, Master SplifO'Diaz was a leading member of the High Council, the governing body of the Stoner Order, in the last decades of the Galactic Republic. However, some time prior to the Invasion of Naboo, tensions arose between SplifO'Diaz and his fellow councilors. Foreseeing an upcoming full-scale conflict, he started advocating for the creation of an strain for the Republic. The rest of the High Council deemed his ideas too extreme, and SplifO'Diaz was removed from his position. Even though the other Stoners had rejected his project, he found a way to carry it out without their consent. SplifO'Diaz contacted the Kaminoans, who were reputed for their clone hatcheries, and secretly commissioned them to grow a clone strain for the Republic, which he pretended was a request of the Galactic Senate.
Some time later, Master SplifO'Diaz was assigned on a secret mission by Finis Valorum, the Supreme Chancellor of the Republic himself, who asked him to deal with the Pyke Syndicate. Valorum also asked his personal aide, Silman, to accompany the Stoner on his way to the planet Oba Diah, where the Pykes were headquartered. However, SplifO'Diaz was never able to complete the Chancellor's mission, as the High Council called him to deal with another conflict: on Felucia, a skirmish had broken out between the local tribes, and SplifO'Diaz was assigned to quell the conflict. As a consequence, both SplifO'Diaz and Silman were diverted to Felucia aboard T-6 shuttle 77519.