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Class overview

Onura-pattern supercruiser


Primary Assembly Forges


Covenant symbol 2007-present.png Covenant Empire
Swords of Sanghelios symbol white.png Swords of Sanghelios
Covenant Remnant.png Covenant remnants

General characteristics

Battlecruiser, Examiner


3,576 metres (11,732 ft)


1,579 metres (5,180 ft)


494.4 metres (1,622 ft)


272 million tonnes

Engine unit(s)

Uden-pattern repulsor engines (3)

Slipspace Drive

Talos-pattern borer


Vranus-pattern dispersal field generators


2-3.8 metres of nanolaminate hull plating

Sensor systems

Esoteric auspex array

Navigation system

Bishop-pattern cruising intelligence

Additional information
  • Ship-to-ship combat
  • Long range fire support
  • Command and control
"Let the Sangheili continue to downplay our importance. They can throw away their lives in pointless battles, but we will defeat the largest of opponents with absolutely no risk to ourselves."
―Precentor Rinn'Go'Aren

The Onura-pattern supercruiser, classified as the DOS-class battlecruiser by the United Nations Space Command, is one of the most specialised models of capital ships deployed by the defunct Covenant empire.

Table of Contents
  1. Operational History
    1. Human-Covenant War
  2. Role
    1. Weaknesses and Counter-Tactics
  3. Layout
  4. Specifications
  5. Variants
    1. Ajenous-pattern
    2. Relentless-pattern
  6. Ships of the Line
  7. Gallery

Operational History

Human-Covenant War


Weaknesses and Counter-Tactics



Sensors and Communications

Earning its designation as an Ordained-class ship in the Covenant fleet, all DOS-class supercarriers are outfitted with an irreplaceable Forerunner shrine-core sensor suite, with their specifications in terms of size, power requirements, and effectiveness differing from ship-to-ship. They all feature an auspex array at their centre, an incredibly-accurate scanner that is unrivalled in terms of accuracy and range by any counterpart currently manufactured by modern races. With it, the Covenant can detect scout ships, defensive facilities, and even subterranean Forerunner relics buried deep within a planet's mantle, usually acquiring all this within a few nanoseconds of arriving in-system. Unusually, it can also independently scan ships that are still en-route within slipspace, and identify optimal places to travel through within the dimension. The exact method in which it does so is not well-understood, although it has been described as independently 'phasing' itself out of sync with the universe in a way that defies current scientific models. While a fantastic sensor that single-handedly turns the DOS-class supercruiser into the best scout ship in the Covenant's disposable, it does have a number of drawbacks. There is a hidden set of security software that must be tricked by Sangheili priests or risk any series of setbacks. In addition, most of those recovered by the Covenant are not in good condition, and because of this, most of the ship's Huragok complement is devoted to its upkeep in some capacity.


Although the Onura-pattern supercruiser is not designed as a stealth ship in the slightest, its focus on speed over survivability meant that it sports a number of complex countermeasure systems designed to fool both automated targeting computers and manual fire from their gunners. An interconnected network of preventive and reactive arrays work in synergy to mitigate any threat that the mothership encounters during their travels, directed by a dedicated team of specialists that work closely with their sensor operators and air arm. All are selected based on their raw effectiveness, even if their reliability and not-insignificant manpower requirements is considered questionable by Sangheili logistics personnel.

Easily the most useful system installed is the supercruiser's Ran'Vel-pattern masking array. A further, albeit larger and more advanced, development of the Ushab-pattern stealth generator mounted on the SDV-class heavy corvette, it has become credited for its ability to directly undermine their opponent's accuracy, especially at distances exceeding 20 kilometres. Unlike its smaller relative, it is unable to completely obscure the capital ship to enemy sensors. This is a deliberate choice, as the power requirements for cloaking a ship of its size would have been impossible to maintain during combat conditions and would have prevented the operation of the energy projector battery. This would have forced the crew to completely deactivate the generators if they wanted to charge their weapons, leaving their ship vulnerable to enemy fire. Instead, the masking array uses a basic distortion screen to minimise its profile to passive and some active scanners. This is paired with a series of multi-spectral hypersinks, which collects the high-energy radiation emitted by the DOS-class, and a series of holographic generators, which manipulates the ship's dimensions in order to throw off weapons fire. Uniquely, it is also connected to a low-level micrex multiscope that resides within its Forerunner sensor-core. Although the Covenant finds that it has limited uses. It is powerful enough to pick up subtle variations in computer circuitry of a turret on a ship that is across the system. A well-trained operator can use to predict what weapons are preparing to fire, and inform the crew accordingly. Tricking it requires a substantial feint on the part of the enemy to deceive them. In the event that this sensor breaks down, a handful of far less sensitive hyperscanner banks are fitted to supplement it. All these systems work in harmony to create one of the best masking networks in all the Covenant, and its compartmentalised organisation means that it is incredibly resilient under fire. Earlier on in the war, shipmasters of supercruisers were careful to mask their wounds with their Ran'Vel-pattern arrays, which prevented the UNSC from obtaining accurate intelligence on their durability and size until after the war.



A predecessor of the newer Onura-pattern, the 3,200-metre-long Ajenous-pattern heavy cruiser is a smaller, much more versatile capital ship that is designed to supplement existing stockpiles of capital cruisers, such as the venerable Varric-pattern heavy cruiser. Retaining a very similar shape and focus, the Ajenous-pattern was never completely replaced by its successor and continued to supplement it in the role of long-range fire support, thanks to its popularity with both Sangheili and Jiralhanae shipmasters.

The Ajenous-pattern ironically has fewer weaknesses than the Onura-pattern supercruiser, and it is capable of defending itself at close range. Sixteen Yrido-pattern plasma cannons have specifically been fitted for the purpose of protecting it, and are carefully arranged to provide full coverage with overlapping fields of fire to both broadsides. These are slow-firing but accurate, and at medium range can supplement other weapon systems to take out small escorts. Thanks to the installation of only two plasma beam emitters, it benefits from improved shields as well, although their age means that they are not as efficient as modern systems. Several silos of Avrin-pattern plasma torpedoes are present, which are reputed to be some of the fastest and longest-ranged weapons of their class in the entire Covenant. Their plasma cores are specifically engineered for speed and range, and are hardened against counter-guidance signals to improve reliability at range, but they lack the potential damage seen in other design patterns. Both of these additions mean that an Ajenous can occasionally be trusted with skirmishing against light opponents alone, and it can fire upon many more targets at range than its successor. Unfortunately, it does not quite have the same punch as the Onura-pattern, as both of its energy projectors are older and less-refined design patterns. In addition, its ancient Orkal-pattern heavy plasma lance is slower to charge and suffers from even worse maintenance issues. If not given enough care, it can break down in the heat of combat, depriving the heavy cruiser of its most powerful asset. Finally, despite its small size, it is slower but quicker to manoeuvre, and it lacks the sophisticated masking array.


The Relentless-pattern heavy cruiser is a modernisation of the DOS-class supercruiser utilised by the Swords of Sanghelios. Created in response to the Great Schism, where the Sangheili found themselves pitted increasingly more against the heavy capital ships hoarded away by Covenant loyalists and warlords, it is hardly the most glorious ship to serve on, where it performs it duty to protect Sangheili space reliably and exceptionally.

As it is based on the older Ajenous-pattern heavy cruiser, the Relentless-pattern bore most of its predecessors features, including its reduced energy projectors in favour of a handful of secondary weapons and a smaller overall size. However, it has been thoroughly overhauled to make it more deadly than ever, with a new shield generator, revised weapons scheme, and improved sensors. Although it lacks the speed and ranged power of the Onura-pattern, it is vastly more versatile.

Ships of the Line

Name Pattern Commissioned Destroyed Notes
Decisive Providence Onura Unknown 2557 Destroyed during Operation: DARK DESCENT
Glorious Malevolence Onura Unknown 2557 Destroyed during Operation: DARK DESCENT
Judgement of Fire Onura Unknown August 30, 2552 First sighted ship of its class, destroyed by UNSC Pillar of Autumn during the Fall of Reach.
Undying Prophecy Onura Unknown 2558 Destroyed by UNSC Infinity during the Requiem Campaign.


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