Mantle's Approach

The Mantle's Approach was the Didact's personal flagship.

Origins
This massive vessel was once captained by the Didact at the height of Forerunner power. Built during the Human-Forerunner War, it served as the Ur-Didact's personal command ship. While not the largest of Forerunner ships, the Mantle's Approach was the fastest and most heavily armed warship in the Forerunner fleet. The ship held a number of escort craft for transport within the vessel, and at its height it possessed enormous support fleets of both manned and automated combat craft, including war sphinxes, sentinels and internally-stored fighters. During the Didact's assault on Omega Halo, it had an escort of thousands of sentinels.

Forerunner-Flood war
During the final years of the Forerunner-Flood war, after being returned to the ecumene from his captivity at the clutches of the Gravemind, the Ur-Didact reassumed command of the Mantle's Approach. He used the ship to travel to Nomdagro and later when he followed the Librarian's ship, Audacity, to the greater Ark. Once there, he remained aboard the the Mantle's Approach in orbit over the Ark, where he was briefly visited by the Librarian. When the Ark fell under siege by Flood forces, the Didact moved the ship to the nearby Omega Halo and used a Composer, a device designed to transfer organic consciousness to software, integrated to the ship to harvest the essences of the human population transplanted on the ring. He then spontaneously departed aboard the Mantle's Approach, headed for Requiem, his primary shield world. He docked the ship inside Requiem and began to process the harvested human essences into new Promethean Knights.

However, the Librarian had trailed her husband on the Audacity, aiming to put an end to his genocidal schemes. With the admission of the Didact's lieutenant, Endurance-of-Will, the Librarian entered the Mantle's Approach and confronted the Didact in the command center. She incapacitated the Didact, placed him in a combat Cryptum previously stored on the Mantle's Approach and sealed the Cryptum inside the core of Requiem. She also sealed the Mantle's Approach itself within Requiem.

Modern era
After his awakening in July 2557, the Didact quickly escaped in his Cryptum and, once the necessary preparations were complete, he recoupled the Cryptum with the Mantle's Approach and took off immediately. He jumped to Ivanoff Station alongside a Covenant remnant fleet, intent on reclaiming the Composer. The Didact test-fired the Composer on the station, then proceeded to Earth to settle his personal war with humanity once and for all. Although Earth had been warned of the attack, the planet's MAC defenses were unable to stop the massive Forerunner ship.

Unbeknownst to the Ur-Didact, however, John-117 had survived the deadly pulse due to the Librarian's intervention. Pursuing the Mantle's Approach aboard a nuclear-armed F-41 Broadsword, the Spartan took out the ship's point defense turrets, allowing the to punch a hole through the Mantle's hull with its fore weapons. The Master Chief then fought his way through the ship, eventually finding the Didact controlling the Composer under an impenetrable force field. Cortana overloaded the shields by flooding the ship's mainframe with her rampant duplicates, allowing the Chief to confront and defeat the Didact with a pulse grenade.

With the Composer already firing upon New Phoenix, the Spartan manually detonated the HAVOK warhead as a desperate last resort. The Mantle's Approach was completely destroyed by the nuclear blast, taking the Composer along with it. The dying Cortana got the Chief out of the ship at the very last moment and created a hard light barrier around him, saving John's life at the cost of her own.

Trivia
Mantle's Approach resembles a Reaper (particularly of the Sovereign class) from the Mass Effect universe. This may refer to the fact that Keith Szarabajka, the voice actor for the Ur-Didact, also voiced the Reaper Harbinger, who shares similar goals to the Didact. Namely, Harbinger seeks to convert all sufficiently advanced sentient life (particularly humanity) into mechanical form, creating a new Reaper.

List of appearances

 * Halo 4
 * Halo: Silentium