The Trayus Core was the innermost sanctum of the Sith Trayus Academy on Malachor V. The core was a claw-like altar—suspended above a massive geyser of dark side energy—stabilized by three bridges that connected to the rest of the Trayus Academy. It was created by the mysterious Sith Empire. The Trayus Core survived the Battle of Malachor V and remained unused until a later time. During the Jedi Civil War, Darth Revan used the Trayus Core on captured Jedi to test their spirit, if they last its powers of the Dark Side, they were killed, if they fell they became Dark Jedi and sent to Korriban.