The Obligator was an Imperial I-class Star Destroyer that was captured by Darth Kalen during his invasion. His engineers heavily modified the warship until it has far larger than any other Imperial I-class Star Destroyer. It became a prison ship. On the Obligator, it was not rare for Prison Troopers to practice there skill with a blaster and electro staff on the prisoners. Kalen gave the Obligator to his apprentice, Darth Maimas in 3 BBY.