On October 28, 2461, Lod Mron was born. He was known as the Vice Minister of Tranquility. His race decided to eradicate humanity before they understand that their religion is not true. For their "gods", the Forerunners, the 3 aliens became the Prophets or Hierarchs.
At the Second Battle of Harvest, The Prophet of Regret is seen leading the Covenant forces in their missions at Harvest to obtain forerunner technology.
At October 20th, 2552, The Prophet of Regret travels to Earth without the consent of his cohorts, and unexpectedly encounters humans. He is pursued and ultimately killed by Master Chief at the Delta Halo (Installation 05) ring world on November 2nd, 2552 at the age of 91.