Xenu

He caused people to be brought to Teegeeack (Earth) and put an H Bomb on the principal volcanoes (Incident 2) and then the Pacific area ones were taken in boxes to Hawaii and the Atlantic Area ones to Las Palmas and there "packaged." His name was Xenu. He used renegades.Various misleading data by means of circuits etc. were placed in the implants.

Source: wiktionary

The documents Scott took are a refinement of Hubbard’s account of Xemu, assertedly an evil tyrant who planted the seeds of aberrant behavior in people 75 million years ago. ¶ According to documents obtained previously by The Times in Los Angeles Superior Court, Hubbard contends that Xemu trapped people in a compound of frozen alcohol and glycol and deposited them in 10 volcanoes. Xemu then dropped nuclear bombs on the volcanoes, according to Hubbard, destroying the people but freeing their spirits, which clustered together and were brainwashed by Xemu.

Source: wiktionary

Seventy-five million years ago there was a galactic confederation consisting of seventy-six planets which had an over-population problem. The head of the confederation was named Xenu and he resolved that he would entice the entire population of the confederacy to Earth (called Teegeeach) and blow them up. […] Contacting the BTs is done telepathically and they are then guided back down the time-track to the moment seventy-five million years ago when Xenu vaporized them, which is known as Incident 2.

Source: wiktionary

"Trapped" made merciless fun of Mr. Cruise and Scientology, but stuck mostly to the church's actual beliefs, including such notions as frozen aliens and a Lord Xenu who ruled a galactic federation of planets.

Source: wiktionary