In 3,640 BBY, after the losses of Darth Karrid and the Ascendant Spear but with the Empire successfully gaining control of Makeb along with the stockpiles of not yet mined Isotope 5, Darth Marr introduced Darth Callidus as the replacement of Darth Decimus to sit on the Dark Council, and together they planned to spearhead the Empire into a new evolution through the militant resources produced by the Forge.