Disclaimer: I don't own Mass Effect. Obviously.
Harbinger felt yet another twinge of annoyance as Shepard interfered with their plans yet again. Scant minutes before the Arrival was underway, the irritating human had thwarted it.
It appeared before the human, showing its displeasure towards the arrogant creature. This would be the last time it would interfere with Harbinger's plans. All of its resistance would be stamped out when the true Arrival took place, and Shepard would despair as its home world was harvested.
As the asteroid – a primitive means of attack, lacking in sophistication – crashed into the Alpha relay, destroying its kinds' immediate gateway into the galaxy, Harbinger took its attention away from the human. There were more important matters to attend to.
In six of this cycle's months, its kind had been able to complete the voyage to the nearest mass relay. The Prothean's last bitter show of resistance – corrupting the Keepers – had put an unexpected hitch into the invasion, but hardly one that they were unused to dealing with. Several former civilizations had attempted the same strategy, and it was an issue easily rectified.
Instead of capturing the center of galactic civilization, the Citadel, as its kind usually did, they proceeded straight to the home worlds of the various races. The Citadel was hardly necessary to their plans, and it would be simple enough to regain control of when needed.
Harbinger focused a majority of its kind into the invasion of the human home world. Their genetic diversity would be useful in constructing a new member of its brethren, one that would replace the Ascended form of humanity that Shepard had so foolishly destroyed.
The humans were easily swept aside, their system immediately becoming the center of the entire invasion. Harvesting was progressing as planned, and the planet provided a source of disposable husks to aid in the Harvest of other worlds.
Harbinger directed the invasion from the human home world, and soon became aware of Shepard's continuing interference.
It did not focus on Shepard's futile endeavor. Many organics had taken similar courses of action in previous cycles, and although Shepard had proved to be a pest, even its most desperate attempts at resistance were doomed to fail.
All the human was doing was postponing the inevitable preservation of its kind, the short-sighted organic incapable of understanding the necessity of the action.
As expected, Shepard was unable to even stem the progress of the Harvest, with numerous colonies being overwhelmed and processed every day, and the home worlds of the various races falling almost as quickly.
This cycle had proved to have few races worthy of Ascendance, and the majority of the organics were useful only for the husks they provided. Some of the species, such as the drell and krogan, lacked sufficient numbers for their preservation to be efficient. Others, such as the quarians and salarians, had debilitating biological limitations. Only three races were judged worthy of the Ascension – the asari, turians, and the humans.
Each of their preserved forms progressed well, although they were each only in the beginning stages of the Ascension.
Shepard continued to prove a pest. Several of its brethren had been destroyed due to the human's direct interference, and each had been performing prioritized tasks. The geth, considered to be possible candidates for the replacement of the Keepers, had been lost. The krogan, although lacking sufficient numbers and less dangerous than the arrogant organics seemed to believe, had joined the war.
Aside from providing more husks, this was nothing but an annoyance. The geth were primitive, possessing such little understanding of its kinds' total goals, unable to truly comprehend a single thought of its brethren. The krogan were easily subjugated, and possessed few ships to aid the organic resistance.
Everything was proceeding as planned.
A human, one of Harbinger's many thralls that believed itself in control, reported of the last effort of the organics. Shepard had gathered the primitive, unsophisticated ships of many species and factions in order to make one last strike against its kind. This effort was futile.
This was yet another constant in the cycle, one that had only been subverted a few times. Organics would band together in an attempt to stall their salvation, unable to comprehend that their doom was inevitable.
It was also reported of the super weapon – the Crucible. Yet another endeavor by the organics that would amount to nothing in the end. They were arrogant to believe that its kind had never seen this weapon, that they were the first to implement it.
Harbinger was struck with annoyance as an unknown component was revealed, the Citadel. The choice of the most powerful mass relay was only logical, and it was obvious even to the rudimentary minds of organics.
The center of galactic civilization was immediately invaded and transported to the ultimate dominion of its kind, the center of their power in this cycle. It was simplicity in itself; the terrified organics who had fled to the Citadel were easily harvested by husks. The humans would be Ascended in the Citadel, completing their preservation in the immortal form of its kind.
It was secure against any attempts by the broken remnants of the human resistance. One of its kind would defend it at all costs, and thousands of husks were stationed around the portal that humans were transported through in order to be processed.
All that was left was the wait for the allied organic fleets, where Harbinger and its kind would crush the last remaining resisting fleets. Any organics who were sufficiently preserved in the resulting destruction of their ships would be processed, and its kind would complete the Harvest in the defenseless home worlds and colonies.
Shepard and the petty array of organics and geth arrived quickly. They were easily subjugated, and the battle for the human world quickly turned into a battle for the organics' very survival.
Harbinger easily destroyed any of the primitive ships that had dared to fire upon him, shredding even the most powerful of their star ships in a single blast of its cannon. The slaughter continued until the Crucible arrived, and the fleets devoted to protecting it joined the battle.
It proceeded safely to the human home world despite all odds, and Harbinger became aware of the full implications of Shepard's impudence. The portal to the Citadel was left unguarded in the wake of its guardian's destruction.
Feeling something that the billions of processed minds that made up its mind almost categorized as fear, Harbinger made its way to the portal. It refused to allow the weapon to be fired – the Crucible's effects were unknown, it had been destroyed or left uncompleted in every previous cycle – and possibly end the cycle that had been in place for more than a billion years.
The loss of the thousands of separate civilizations that had been preserved was unacceptable. The Protheans, whom were vastly superior in technological advancement in comparison to this cycle, were unable to stall their progress, and it would not allow these inferior beings to end it.
Harbinger easily struck down the forces that rushed at the portal. They were exposed, and any cover they were able to find was easily turned into a molten heap of slag by its weapons.
It identified Shepard as the last one its beam hit, and Harbinger lifted off to rejoin the battle once it saw the impudent human struck by the beam.
Despite its best efforts, Harbinger was unable to destroy the Crucible in time. It had sustained somewhat significant damage, and the defending fleets were nearly completely obliterated, but it had managed to dock with the Catalyst.
It did not work, however, and Harbinger directed its kind to focus their great power against the Crucible. This would be the organics' last attempt at resistance, and the Harvest and Ascendance of the organics would proceed as planned.
Just as Harbinger prepared to strike the final series of assaults against the Crucible, and destroy any remaining hope the inferior organics possessed, a supernova of bright light erupted from the Citadel.
As the light passed through its kind, Harbinger became aware of another force, immeasurably powerful, overwhelming it. Despite all attempts to disobey, to continue the preservation of the organics, it found itself and its brethren leaving behind the broken organic forces.
And then Harbinger, scourge of countless galactic civilizations, oldest amongst the ancient biomechanical gods that floated through the cosmos, and preserver of the organics knew no more.