Nat-Sem was a male Jedi Master serving the Jedi Order and the Galactic Republic prior to the rise of the Galactic Empire. Taking Padawan Roan Shryne as his apprentice, he trained the boy to Knighthood before being killed in the Battle of Geonosis at the start of the Clone Wars.
Nat-Sem was a Force-sensitive who was discovered by the Jedi Order and trained in the ways of the Force eventually attaining the rank of Jedi Master. During his time in service to the Republic, Master Nat-Sem selected the young Roan Shryne as a Padawan, training him in the ways of the Jedi as he had been taught. Traveling the galaxy together, Shryne eventually learned all he could from Nat-Sem and passed his own Trials before becoming a Jedi Knight. Going their separate ways, Nat-Sem and Shryne fought side-by-side in the Petranaki arena on Geonosis when tensions between the Galactic Republic and the Confederacy of Independent Systems erupted in a conflict there. Fighting bravely alongside members of the Jedi High Council and their brother and sister Jedi, Nat-Sem succumbed to blasterfire shortly after Master of the Order Mace Windu decapitated bounty hunter Jango Fett. Watching his former Master fall, Shryne went onto survive the war and the initial stages of the Great Jedi Purge before falling victim to Sith Lord Darth Vader's blade on Kashyyyk.
- Dark Lord: The Rise of Darth Vader (First mentioned)