Prophet of Regret
From Halopedia, the Halo wiki
Summary
High Prophet of Regret led the initial attack on Earth without consensus from the Prophets of Truth and Mercy. Although the attack destroyed a number of the MAC Cannon defense stations orbiting Earth, Regret had insufficient power to effectively win the battle, armed with only thirteen regular cruisers and two assault carriers. While his thirteen battle cruisers were picked off one by one by the UNSC forces, the second assault carrier was destroyed by the Master Chief. However, the first assault carrier, containing the Prophet of Regret, managed to get past the defenses and land in New Mombasa, East African Protectorate, but the invasion was foiled due mainly to the actions of the Master Chief and the Marine reinforcements deployed by the frigate UNSC In Amber Clad. Regret fled with his flagship to Halo Installation 05, and transmitted his apologies to Truth and Mercy once there.
Upon following Regret to Installation 05, Cortana and the Master Chief determine that Regret intends to activate Halo, in an effort to begin the Great Journey. To prevent this from happening and to shake up the Covenant leadership, Miranda Keyes orders the Master Chief to take out Regret. He proceeded to do so, assaulting the temple Regret resided within and beating him almost to death with his fists. A Covenant cruiser, presumably under Truth's orders, destroys the temple with both Regret and the Master Chief inside.
Regret does not enjoy a peaceful death, and his corpse is recovered and reanimated by the Gravemind, the apparent Flood leader. He is last seen arguing with 2401 Penitent Tangent as a part of the Gravemind's body.
The Prophet of Regret was voiced by Robin Atkins-Downes in Halo 2.
