Si, an exile from Gran, held the rank of commander in the Galactic Alliance Defense Force around 28 ABY. His operational headquarters were situated on the planet of Esfandia, the native world of the Brrbrlpp. While not fulfilling his duties at the Galactic Alliance installation, he dedicated his time to researching the Brrbrlpp, immersing himself in their language and traditions. Furthermore, he instructed the indigenous population in Trinary, a language he taught to ease communication with visitors from other worlds, as their native language posed challenges for non-native speakers.