Bane takes the long-abandoned Sith title of Darth, leaves the Brotherhood, and travels to Rakata Prime. There, he discovers a Sith Holocron left behind by Darth Revan. Bane completes his training, learning numerous Sith techniques, including the "thought bomb" designed to kill all Force-sensitive beings in reach. He sends this to Lord Kaan. Bane then devises the "Rule of Two": only two Sith Lords, a master and an apprentice, are allowed to exist at one time ("One to embody power and one to crave it.")