Ydra Kilwallen Sibwarra was a Jedi Knight in training during the time of the rise of Emperor Palpatine and his New Order. A woman from Chandrila, Ydra was a Jedi Knight as well as a wife and mother. Her young son, Dev Sibwarra, proved to be strong in the Force, even as an infant. However, as the Emperor scoured the galaxy hunting down the Jedi Knights, Ydra was forced to flee Chandrilia to avoid being killed. Hoping to avoid Palpatine's Jedi Purge, Ydra resolved to flee the Core Worlds and settle on the remote Chandrilian colony world of G'rho, where her brother, Trig, resided.
With the help of her brother, they convinced G'rho's militia boss to hide her as a historian. Working on G'rho, Ydra barely made enough to feed herself and Dev, but nonetheless felt safe, as the world was close to the Outer Rim. Unfortunately, G'rho was a world that had caught the interest of a group of reptilian aliens known as the Ssi-Ruuk. From a planet close to the Unknown Regions, the Ssi-Ruuk had a very advanced technology and mastered hyperspace travel. Unfortunately for the galaxy, for reasons unknown, the Ssi-Ruuk began subjugating worlds in their part of the galaxy.
As G'rho came under attack, the Ssi-Ruuk captured Ydra and killed her, taking her life essence as a power source. Enteched into the Ssi-Ruuk power supply, Ydra Kilwallen Sibwarra became one with the Force. As for her son, the Ssi-Ruuk captured him and used him and his affinity in the Force to help them as they continued their thrust for galactic superiority. It wasn't until years later that the Ssi-Ruuk were finally defeated at Bakura at the hands of Jedi Knight Luke Skywalker.