Disclaimer: I do not own Halo or Mass Effect.

A part of the Legacy Effect World Building Project

The Seventh Age of Conflict (Covenant-Krogan War)

Circa 1570 CE

Circa 0632 AR

The krogans had dug deep under Tuchanka's mined out crust. Mountains were hollowed out and turned into high-impregnable fortresses that descended many kilometers under the earth. The earth was overturned so the krogans could bury fusion reactors for their surface-to-space cannons. A billion krogan warriors polished their armor and trained while a billion more worked tirelessly among machines to turn Tuchanka into the largest battle station in history.

The space above Tuchanka was also rifle with activity. A thousand warships aggressively guarded the krogan homeworld. A thousand more ships patrolled the space between worlds in packs of five with equal ferocity. Kanin and Kruban, two worlds in the Aralakh system, were completely mined out to build massive star fortresses that were bristling with the largest cannons and protected by multiple layers of kinetic barriers. These fortresses drifted through space via powerful fusion engines.

Two such fortresses guarded the mass relay. The wrecks of several Citadel dreadnoughts and a dozen smaller ships that had tried to act as the spearhead for their invasion proved the futility of trying to break the gauntlet by mass relay.

Every ship here was captained by a krogan who had fought and lived against the Citadel and their new guard dogs, the sangheili and turians. They had all been tested in battle and emerged stronger for it. That was good. The krogan needed all the warriors they could find.

For war had come to Tuchanka.

SLIPSPACE RUPTURE DETECTED.

Five billion kilometers from Aralakh space became twisted and distorted. Microscopic black holes appeared, fused and enlarged. Radiation spilled into real space and dissipated into the interstellar void just as quickly.

The Fleet of Absolute Justice did not.

One hundred and twenty Covenant warships, arrayed perfectly in a staggered cube, powered their engines and set course for the krogan homeworld. Laser fire burnt away dozens of deep-space warning systems that the krogan had scattered throughout their system. Hundreds of krogan warships and a dozen dreadnoughts changed their courses.

SLIPSPACE RUPTURE DETECTED.

Space twisted again.

The Fleet of Righteous Purpose had arrived.

Several krogan dreadnoughts turned to face this new armada. A dozen star fortresses lumbered behind.

SLIPSPACE RUPTURE DETECTED.

Eighteen billion kilometers from Aralakh, space ruptured.

The Fleet of Harmonious Light had arrived.

Thirty star fortresses pushed their engines to their limit.

From the bridge of the Covenant battleship Honor of the Fallen, the second Arbiter of the Second Illumination watched as the greatest combined fleet in the history of the Covenant charged the krogan defenses. Centuries-old Joyous Exultation-class battleships and their newer Retribution-class counterparts fired their particle cannons and mass accelerator cannons. In between the lances of particle fire and oversized kinetic ships, fighters and bombed clashed in the hundred with their hardier krogan counterparts. Krogan barriers flared and collapsed. Fusion reactors exploded. Krogan warships were indeed formidable but they were hideously vulnerable to particle cannons.

A krogan dreadnought fired it four spinal cannons at the battleship Indomitable. The first two shells knocked its barriers out. The third tore a hole through its armor. The fourth ripped apart its reactor and vaporize the ship and its crew.

Seven more krogan dreadnoughts opened fire.

Fifty star fortresses did the same.

Scores of miniature suns flared into existence just for the briefest of moments.

The mass relay spun to life.

"Your Excellency, we are in range of their fortresses."

"Have the Fleet of Harmonious Light continue its advance inward," the Arbiter ordered. "Pull the rest of the fleets back just enough to give these savages a chase. We must attract as many of their ships as possible. It is time for our allies to impress us."

Up until the Covenant stumbled on the Citadel via mass relay over a century ago, the sangheili and the san'shyuum had presumed that the only way to travel between the stars was by puncturing a hole in reality and traversing the slipstream. The discovery that one could apply the mass lightening capabilities of Element Zero so a ship could accelerate faster than light itself sent more than one sangheili thaumaturgist into a frothing frenzy. Several prominent thaumaturgist's claimed this to be a hoax. They committed ritual suicide when they had been proven wrong.

Of course, the same could be said for the asari, salarians, the turians, and the other minor races that made up the Citadel alliance. To them slipspace was an oddity, another dimension that held very little interest. The fact that the Covenant used slipspace for interstellar travel was equally astounding, albeit their scientists were a little more accepting of this reality.

Since joining the war against the krogan, the Covenant had exploited their "mastery" of slipspace to case a great deal of harm to the krogan.

Because as of right now the Arbiter had attracted more than half of the defending krogan ships towards his combined fleet. Hundreds more were engaging the Fleet of Harmonious Light, which was making its way towards Tuchanka.

That left at least several hundred warships for the Citadel and turian fleets to deal with.

"Fair enough odds," the Arbiter muttered.

Three ugly rectangular ships were spat of the relay. They had no weapon mounts or missile silos. Their unadorned hulls were immediately torn into by the bristling array of cannons of the two star fortresses. Their kinetic barriers had fallen almost immediately. The boxy ships held together, however. Meters of armor had been blasted apart but more remained.

The three of them accelerated on a crash course for the star fortresses. The weapons fire became more erratic as the boxy ships sped closer. Two rammed through the layers of kinetic barriers of one while the other pushed its way into the other. Inside the broken hulks, thousands of krogan warriors surrounded the front of the crashed ships. Perhaps they expected to fight an invasion force. Capturing a star fortress would look good for any enemy commander.

In fact, that is what the krogan inside the boxy transports though too.

Unfortunately for both krogan factions, that is not what the STG had in mind.

The fortresses exploded, scattering their atoms in all directions. Seconds later, the turian fleet shot through the relay followed by the rebuilt fleets of the Citadel - hundreds of dreadnoughts, cruisers, and frigates emptying out hundreds of fighters themselves. White streaks shot across space as the krogan, turian, and Citadel fleets exchanged fire with each other. Missiles were blown out of space by the droves.

Urca was impressed. He had not expected that.

"Have all ships resume the advance. Focus fire on the krogan dreadnoughts. Raise Supreme Commander Othro 'Usumee on the comm. Have his fleet reinforce the Harmonious Light. Let us show the krogan how true warriors fight."

He tapped a button and opened a channel on a fleet wide broadcast. He took a deep breath and spoke: "Today marks the end of this long and brutal war. Never against will the krogan threaten our children. Never again will the krogan threaten our Covenant. On the eve of this holy crusade, I invoke the words of the Golden Praetorian: Once again raise the flag of salvation! Onward warriors of the Covenant! Onward heroes of Sanghelios!" He paused and then added, "Glory to the Covenant!"

A hundred voices chanted back, "Glory to the Covenant!"