Prophet of Regret

The High Prophet of Regret was the youngest of the three High Prophets that lead the Covenant High Council during the Human-Covenant War. Rash, ambitious, immature and naive compared to the other Prophets, Regret originally served Vice Minister of Tranquility, where he worked frequently with Sangheili and had adopted some of their personal traits, such as a preoccupation with honor and personal arms. However, he also exhibited traits of alcoholism and smoking.

Regret's character was voiced by Robert Atkin Downes.

Twenty Third Age of Doubt
During the 23rd Age of Doubt, 2524 by the Military Calendar, Regret held the post of Vice Minister of Tranquility. He was unique among the Prophets for his confrontational demeanor, a trait he gained from working with Elites. He informed the Minister of Fortitude about the existence of Harvest and what they believed to be a vast repository of Forerunner artifacts. (These "artifacts" were the Reclaimers on the planet.) After conspiring with the Fortutude to gain these artifacts for their own use, he helped him by pretending to sympathize with those blacklisted from reproducing due to inbreeding, which included the Prophet of Restraint. After pretending to be the father of a child Restraint had unlawfully fathered, Tranquility blackmailed Restraint into stepping down from his position as High Prophet.

Before their coup, the Prophets visited the Oracle, an ancient AI stored in the Forerunner Dreadnought that had not spoken to anyone for hundreds of years. When the Luminations of Harvest were entered into its matrix, it revealed the symbols had been misinterpreted -- that humans were equals to the Forerunner and the Covenant had been mistaken in their beliefs. As it tried to launch the Dreadnought from High Charity the Lekgolo worms inside the Dreadnought short-circuited it and stopped Mendicant Bias. Fortitude, Tranquility and the Philologist made the decision to disconnect the Oracle from the ship and decided to eradicate humanity before any of the Covenant learned that the most basic premise of their faith was false. As such, their ascension was made, taking the names of Truth, Regret and Mercy.

War
After or during the Second Battle of Harvest, Regret discovered a Forerunner relic buried in the planet's northern polar region. Dispatching a force led by an Arbiter, valuable information was recovered. With UNSC forces closing in however, Regret ordered that the relic be destroyed to prevent the retrieved information from falling into human hands. Against his instincts, the Arbiter obeyed.

Three years later, Regret was present at the Battle of Charybdis IX, with his personal Assault Carrier, Infinite Sacrifice, where he oversaw Thel 'Vadamee, and the glassing of the planet. He then called upon Thel to find the source of human-modified Covenant Weapons, and bring them to the Prophets. Little did Regret know, that he was infact interfering with the Prophet of Truth's plans to find the location of all the Human colonies and Earth. However, their plans eventually fell back into tandem

Regret also served during the destruction of Halo Installation 04 and helped condemn the Sangheili Supreme Commander (later the Arbiter) who was responsible for the loss of the ring.

Earth
The Prophet of Regret led the first attack on Earth with a small fleet of two Assault Carriers and thirteen Battle cruisers. He may have been directed to Earth by a Forerunner artifact on Coral to search for the Ark, but he apparently had no knowledge of a human presence on Earth or that it was his enemy's home world. He sent Ranger Elites and Boarding Craft to destroy the Orbital Defense Platforms Malta, Athens, and Cairo, so he could push through into the heart of Africa. Despite the Master Chief's actions, his ship made it to the ground and deployed the first full-scale invasion force of Covenant on Earth.

After landing in New Mombasa, Regret's forces searched the city supported by Scarabs and many Phantom dropships. As the Master Chief approached his Carrier, Regret's ship initiated a Slipspace in the middle of New Mombasa to escape and regroup. The forces generated by the jump Heavily damaged the city. The move was so surprising that only the In Amber Clad and four other UNSC ships were able to follow the Carrier.

Delta Halo
""I shall light this holy ring, release its cleansing flame, and burn a path into the divine beyond.""

- Regret

Regret's Carrier deployed ground and infantry forces onto the surface of Installation 05, and set up a presence around a temple in the middle of a lake, from which Regret began his religious sermons. He transmitted an apology to the Prophet of Truth, indicating that he couldn't have known that the humans would be there or in such force. Truth responded that only Mercy had spared him from public condemnation. Nevertheless, High Charity and the Second Fleet of Homogeneous Clarity rushed to the new Halo, and a flight of Phantoms was deployed to rescue the Hierarch.

In Amber Clad arrived in system soon after and deployed ODST forces on Installation 05 along with the Master Chief to locate and kill Regret. The operation was a success, but soon afterward High Charity made a jump to the ring and ordered one of the nearby ships to use its Gravity Lift to destroy the temple, nearly killing the Spartan and leaving Regret for dead.

Regret's body was later assimilated and reanimated by the newly formed Gravemind. He expressed annoyance with another captive of the Gravemind's, 2401 Penitent Tangent, and reacted to the presence of the Arbiter, warning him to forgo any heretical suggestions made by the Monitors and the humans and to pursue the Great Journey. What remained of Regret was destroyed with the Gravemind when the replacement for Installation 04 was prematurely fired by the Master Chief and Cortana.

Gameplay
The only weapon Regret has is his Gravity Throne, seen in the level Regret. Regret is heavily guarded by Grunts and Honor Guard Elites. The throne is equipped with two Gravity Cannons that glow bright orange and are a modified version of a Hunter's Assault Cannon. It allows him to teleport a short distance away. Regret can be knocked out of his throne and shoot the player with a Plasma Pistol before teleporting back to his chair. The only way to defeat him is to board his throne and melee attack him. However, rockets and energy swords can weaken him. Though this will not kill the Prophet it will reduce the number of melee hits needed to kill him.

Trivia

 * Regret's title is ironic, like the names of all the other High Prophets, as he never showed any regret for his actions.
 * The Prophet of Regret is still alive in Halo 2 by way of the Gravemind.
 * During Regret's boss battle, if you are swift enough, you can board his throne and punch him as if you boarded a tank. You can also teleport with him throughout the map.
 * If you melee Regret's hologram in any level, you will lunge towards him. The lunge is more noticeable if you use an Energy Sword.
 * On holograms of Regret, if you stand on the holo-panel or crouch on it, you can see that Regret has real eyebrows, even though its a hologram.
 * He will be appearing in Halo Wars as a Hero unit and will be able to be upgraded.
 * It is possible that Regret's carrier from Halo: The Cole Protocol, Infinite Sacrifice, is infact the Assault Carrier he used during the First Battle of Earth.

Related links

 * Prophet of Mercy
 * Prophet of Truth