Eternal Oath-class attack ship

"Find me a working Forge, and a Huragok in which to operate it, and I will gladly strip them from my fleets. Until then, I am not in a position to deny myself even the smallest and most pathetic of the Covenant."

- Warmaster Turrus, referring to his fleet of storm cutters.

The Eternal Oath-class attack ship, designated as the DAS-class storm cutter by the UNSC, is a first-rate Attack Ship classification that is utilized by the former Covenant Empire and their successors. The smallest warship in their fleet in terms of size, the storm cutter is not intended to be used in larger Covenant fleet structures, although it has been pressed into such formations before. Rather, it is a privateer craft tasked with low-priority, general-purpose duties, and so carries its own strikecraft detachment and troops to remain independent. Its duties are focused around policing, tailing suspect spacecraft and either providing continuous information on their movement, or intercepting them. Renowned for its agility in battle, the Eternal Oath-class isn't as well armed and protected as it should be. As a result, the lower-class crew must be selective about the targets they harass and be granted support when engaging anything larger than other corvettes.

A comparatively recent addition to the Covenant fleet, the Eternal Oath-class attack ship has always been shunned by the Sangheili, with most instead crewed by the Kig-Yar and Jiralhanae. Resigned to operations close to populated habitats and worlds, their crews lacked the zeal of professional military warships which saw many directly preying on the very civilians they are supposed to protect. Because of their untrustworthiness, few ever partook in the expeditionary wars that the Empire fought, and those that did typically performed scouting efforts and captured fleeing vessels for later analysis. So weak and expendable are they that the Covenant rarely followed up attempts to recapture them, merely content with destroying them when confronted.

With the dissolution of the Covenant, the lack of military warships of any kind saw even the humble Eternal Oath-class attack ship being begrudgingly used by successor-states as well as the traditional Kig-Yar pirates. With so many factions lacking the resources to man, build, or even maintain their armadas, storm cutters took on far more dangerous roles than they were ever designed for. While some still earned profit by continuing to raid logistic transports, for the first time these corvettes found themselves on the frontlines, skirmishing and jockeying with rival nations and making often-fatal attempts to capture their hostile cruisers. Regardless, for better or for worse, storm cutters are forced to be treated as valuable and respected assets, and so are often granted the rewards that come with such a position.

Armament
"Took us almost an hour to chase it off for good, but by that time the Charlie-Sierra had us dead in the water. I just kept waiting for them to finish us off."

- Cpl. Dan Sanders

While Covenant ships are universally known as being several times more powerful than their UNSC equivalents, the Eternal Oath-class is an exception to that rule. This is mostly due to the inadequacy of its weaponry, which is partly constrained by its small size and lack of plasma torpedoes. This is also explained by its design brief, which emphasizes that these corvettes must disarm and strip enemy ships of their mobility. The systematic elimination of major systems only serves to push any fight into its favor the longer they drag on, and in numbers they are more than capable of leaving a destroyer helpless to fend off a boarding party.

The four Emri Ka-pattern light plasma lances are the most powerful weapons installed aboard these storm cutters. The smallest in their class, these fire precise pillars of plasma that burn and cut their way through most materials that are used in starship construction. Direct impacts rip away hull plating and viciously shakes the target, causing further damage deeper within a warship that must be repaired. Very, very few skilled gunners have proven its accuracy and range by striking a reactor a few kilometers away with less than a meter of clearance, to devastating results. Although their beams are weak enough for the emplacements to withstand continuous operation, firing all four at once places an immense strain on its reactor that makes it impossible to recharge shields and operate most other weapons, so they are only fired sequentially or in pairs for very short periods. While it wrecks havoc on lighter grades of armor, heavier alloys such as titanium-A battleplate are resilient enough to limit their effectiveness, which stops them from being a reliable means to harm opponents.

To address this, four Enteros-pattern plasma beam emitters are fitted, again the lightest of all related systems. Far more forgiving on the corvette's power supply, the Enteros is clearly not intended for ship-to-ship combat, as its broad beam is far less lethal per-area when compared to all other Covenant weaponry. It lacks the kinetic punch exhibited by other naval guns, and so struggles at buckling the superstructure. However, most of its damage is inflicted as sustained beams that transmit a very large amount of superheated plasma, which has proven very effective at reducing thick plates of solid armor into a free-floating gas. All four of their turrets are mounted on the bow of its lower pods, which allows all of them to concentrate their fire on a single opponent. This lends them towards an early, shorter-range weapon, weakening the opponent's armor enough for later light plasma lances to leave it stranded in space.

For defensive purposes, four Phot Et-pattern pulse laser turrets can be found in covering angles around the cutter. A mutated version of the standard Phot-pattern turret mounted on the, a weapon that prides itself on its rapid rate of fire, the Phot Et turns this up to a ludicrous extreme. Its focusing chamber is overclocked far beyond its established limits, which normally decreases the radiation wavelength to create a much more destructive beam. This is paired with fast-cycling lenses that cuts down the period of laser fire in favor of releasing a staggering amount of projectiles, which weakens the individual projectiles. Although a very good defense against missiles and space fighters, the cooling systems cannot cope with the extreme amount of energy that is sifting through the turret. Issues such as vastly decreased accuracy are a symptom of this, and gunners are trained to allow the Phot Et guns to temporarily shut down in order to return to optimal levels. This creates a weapon that, while it performs brilliantly at defeating short barrages of Archer missiles, it leaves much to be desired against fighter constellations and as a knife-fighting naval gun.

Defenses and Countermeasures
Like all ships in the Covenant fleet, the Eternal Oath-pattern storm cutter is equipped with a wide range of supplemental systems that protect the ship from harm, either by evading fire or by reacting to hull breaches where possible. Neither its hull nor its shields are particularly strong, so storm cutters focus their efforts towards avoiding it entirely in the hopes of never having to test their damage-control systems. If these fail, they typically must fall back or risk losing their ship to even light ship-to-ship fire.

If an opponent manages to land a hit on this corvette, a single Al Ren-pattern dispersal field generator attempts all it can to stop it from breaching its delicate armor. Generally-regarded as an up-scaling of the shield generators employed on Seraphs, it projects a transparent barrier of light that the cutter's superstructure a few meters above the hull. Arrays of emitters and capacitors generate the barrier across three distinct sectors, and the generator is clever enough to dynamically adjust power across the entire system in order to maximize protection, with the process taking picoseconds to complete. Due to the physics associated with them, shield strength grows inversely with impact area, and at its strongest point the entire array can almost withstand a single frigate-strength MAC strike. This is not much when compared to other Covenant ships, and this also showcases its main weakness: if it is attacked across multiple regions, then shield efficiency falls and it becomes likely that the generator will expend all the energy stored in its capacitors and subsequently fail. In addition, because the distortion screen is integrated over the Al Ren 's barrier, it requires a period to stabilize the barrier before it can recharge. Regardless, while the refresh rate is slow and has a high delay time when compared to other shield generators of similar age, it is nevertheless quicker than most older systems. Its only other advantage besides protection is that the flares from impacts are far more subtle, only restricted around the area of impact, and the recharge flare is also nearly impossible to see optically.

As stated above, the Al Ren-pattern generator is closely linked with its cloaking device, a Kix'Er-pattern stealth field generator. Somewhat more sophisticated than the Ushab-pattern used on the larger Sacred Visionary-class bellator, the Kix'Er is designed to fool active scans at medium range, and mask its emissions so passive sensors are unable to detect it until it arrives into engagement range. While hyperscanners can see through this deception quite easily, more primitive human sensors require sustained scans to do the same, which gives it enough time to sneak up on even the most alert UNSC vessel. Phased energy field sinks vent the radiation from its repulsor engines directly into another dimension at periodic intervals, while a rotating distortion screen and limited particle manipulation above its shields generates a convincing invisibility cloak on optical, and radio sensors. A multispectal hypersink completes the suite, which must be vented periodically in order to avoid the radiation held within to kill the crew. Although powerful, it is outclassed by more refined systems and the lack of a dynamic adjustment computer allows for enemy systems to eventually detect the anomaly.

To bolster its agility in battle, the Eternal Oath can call upon a variety of electronic countermeasures to protect itself. Its Loardab-pattern combat disruption suite built into the two lower booms features an active jamming system, holographic deception field generator, and nanobot swarms for defensive purposes. Using information from its damage-control computer, it can slowly stretch and manipulate the visible profile of the cutter, hide breaches in armor, and even project an independent hologram very close to it. In conjunction the stealth field generator, it has been seen to project the Covenant's equivalent of a smokescreen. This array is mainly used to preemptively throw off the aim of naval coilguns, although recently-developed techniques using point-defense guns as spotters has limited this somewhat. An exotic wave emitted between its split hulls interferes with Archer targeting computers at short-range, although this is usually not enough to prevent them from impacting it. The nanobot swarms can release the same signature to draw them away, and because they emerge from where the signal originates on the cutter, it lends credence to the theory that the Loardab-pattern cannot generate this jamming system independently. Regardless however, the nanobots are mainly there to rapidly seal off hull breaches, cutting and aggressively refining spent nanolaminate to repair the ship. The associated intelligence which coordinates them gives no concern for the ship's crew, and there have been cases where their repairs had caused rooms to collapse and entomb unwary individuals.

Mutan Et-pattern
The default design pattern of the Eternal Oath-class as of the Human-Covenant War period.

Ovakrellan-pattern
"Our eyes are yours."

- Chur'R-Arre, shipmaster of the Committed Whisper.

A mutated design pattern of the basic Mutan Et-pattern cutter, the Ovakrellan-pattern stealth cutter is a highly specialized corvette that is only found in the Ministry of Fervent Intercession. Staffed by a twelve-man team of lower-class species selected based on their fanatical devotion to the Great Journey, it is deployed as an infiltration and spy ship for Zealot teams, intercepting any-and-all information related to the sighting of artifacts and safely extracting them from the battlefield.

Based around the central hull of the base model, the Ovakrellan is named after an elusive reptile that makes its home on the banks of the Borinam Archipelago on Sanghelios, which only strikes once it knows it can overpower its prey. This likeness has influenced the shape of the cutter. Although it is equipped with unusually-resilient shields for its size, it is not designed for combat. Its armor is too thin to reliably take hits, and any space for weapons are occupied by a modest array of hybrid pulse laser and plasma cannon turrets. In addition, it is fairly slow by Covenant standards, with a single boosted gravity propulsion drive mounted beneath it to attain average speeds for a short time. Instead, it makes up for this with the single most effective cloaking system in the entire Covenant fleet, which has fooled some of the most advanced sensors in the UNSC, as well as rendering it optically invisible. This allows it to easily slip beneath defensive grids. A sophisticated array of electronic countermeasures are fitted, and are capable of disrupting the operation of primitive Archer missiles as well as more exotic plasma bursts. The only other standard feature is a short-range borer, which therefore means these ships must be deployed from a mothership. There appears to be two different variations of the Ovakrellan in service, one with outstretched fans potmarked with hyperscanner relays and an antimatter mine dispenser, while the second model instead has a modular hangar bay capable of carrying either a single Spirit dropship or two Seraphs, in addition to mission-specific material.

The Ministry of Fervent Intercession was notoriously protective regarding external data on the stealth ships, and ruthlessly monitored ex-crewmembers in the event that they divulge classified information. As a result, the UNSC was only aware of the corvette's existence in 2552, when one was discovered and destroyed above Sigma Octanus IV. However, the testimony of a former Zealot has revealed dubious information of these ships, which if true, revealed that a detachment of these ships bypassed the orbiting fleet of Reach. They established the vast network of stealth pylons and teleportation spires, allowing the Covenant fleet to smuggle ships and armies onto the planet's surface.