Ossus shall be like no other battle. It shall be not only a battle between nations, but between the very essences of the Force.
The Battle of Ossus, also known as the Attack on the Jedi Praxeum and the Jedi massacre, was one of the most devastating battle for the Jedi Order throughout the entire Sith Crusade and an ideological turning point in the aims of both sides. Following the Battle of the Cron Drift the Jedi found themselves on the very edge of Sith space and, fearing for the population of Ossus, ordered the immediate evacuation of the planet, sending a request for assistance to all whom would listen.
Awaiting the inevitable attack, the Jedi were surprised by the arrival of the Dark Lord of the Decreton Empire Darth Abeonis, who seemingly wished to offer terms of surrender to the Jedi; an offer few Jedi were willing to even consider, instead preferring to apprehend the former Jedi there and then. Regardless, Luke Skywalker allowed Abeonis to speak; and was left shocked by his revelations, despite ultimately turning him down.
Enraged, the Dark Lord returned to his fleet and commenced with the attack, decimating vast swathes of the planet and hemming the Jedi into their Academy, although incurring heavy losses in the process. The battle raged for the remainder of the day, and into a second, with the Sith finally invading the Academy itself. Led by Darth Micail, the Sith forces massacred the defending Jedi and Alliance soldiers wherever they could, before finally retreating.
As the Sith returned to their fleet, the newly arrived Galactic Alliance fleet did what little they could to combat their much larger Sith counterpart. Abeonis was concerned with little more than remaining in orbit long enough to gather his forces, and as soon as this had been achieved the Sith fleet left the sector; leaving a devastated Ossus behind them.
As soon as the last evacuees had left the planet the Ossus sensor array located on Ossus' moon detected a lone Sith vessel on a course to the planet. The lone Sith vessel informed the Jedi that it wished to discuss peace negotiations. Although suspicious, the Jedi allowed the vessel to land.
Upon landing it quickly became apparent who exactly was on board the Sith vessel. It was Darth Abeonis. Unsurprisingly most of the Jedi said that they should take him prisoner and attempt to end the war, but Luke Skywalker decided against this. He took Abeonis to the Jedi council room and asked him what he wanted.
A shocking revelationEdit
All is not as it seems, Luke.
It was then that Abeonis informed the Jedi Master the reason he had gone to war in the first place. Not to destroy the Jedi and conquer the galaxy, but ironically, to install the Jedi as masters of the galaxy. He informed Luke in a vision he had had before the conquest of Csilla, Cal Omas, Chief-of-State of the Galactic Alliance, would be responsible for the destruction of the Jedi Order by turning the galaxy upon the Jedi much like Palpatine had done eighty years before.
He then said that, in his mind the only way to prevent this was to make heroes of the Jedi once more; and the only way to do that was to show the peoples of the galaxy that even after the Jedi have been almost utterly decimated, they could still fight on.
So he gave Luke a choice. The Jedi could leave Ossus without fear of Sith attack and travel to Coruscant. Once there they were to remove Cal Omas from power and secure control of the Galactic Alliance; only then would peace between the Sith and the Jedi be possible. The other choice was that the Sith attack Ossus before the relief fleet arrived and kill as many Jedi as possible. Once the relief fleet arrived the Sith would leave and the Jedi would be shown as heroes.
Although I see your point of view, my loyalty to the Alliance, and its Supreme Chancellor is beyond question.
—Reluctantly, Luke choose the second option
Enraged at this defiance Abeonis left, and the Sith fleet arrived.
As soon as Abeonis left the planets atmosphere the Ossus sensor array detected a great mass of Sith warships on an intercept course with the planet.
Skywalker ordered everyone on the planets surface to the Jedi Temple in order for it to be defended properly. The only trouble with this was that it left the city wide open to be occupied by Sith forces, something pointed out by both Jacen and Ben.
Acknowledging this Luke then ordered several detachments of Alliance troopers to defend the few blocks around the entrance to the Temple, but by then it was too late; the Sith had already landed and those few troops that left the safety of the temple were instantly killed by the Sith Knights leading the attack. Then they attacked the temple itself.
Wave after wave of Sith struck the great doors of the Jedi Temple and, at first it look as if the Jedi would hold; but slowly they began to fall back. Eventually the Sith broke through and into the central courtyard of the Jedi Temple, killing many hundreds as they went. Determined to hold the assault Kyle Katarn ordered his men to hold firm and stall the assault, with some degree of success.
After a further two hours of duels and battles the Sith fell back slightly to secure their gains in the temple. The Jedi took this advantage to fortify their positions and regain their strength.
The second waveEdit
On the second day of the battle the Jedi suddenly found themselves being overrun by a new wave of Sith led by Darth Micail. They quickly breached the Jedi defenses and, before long, were at the far end of the main courtyard. Desperate to hold Kyle ordered his non-Force sensitive units to pull back and leave the "job" to the Jedi.
Over the next few hours the attacks slowed down in numbers and frequency until, finally, they stopped altogether. Suspicious, Kyle and Jacen (who had recently joined him) left their positions to find the areas of the temple under Sith control empty. The Sith had fled because the Alliance relief fleet had arrived.
The space battleEdit
Although the Alliance relief fleet had arrived the Sith could not pull out until their entire force on the planet had been retrieved.
Over the next few hours, as the Sith warriors returned to their vessels the Sith fleet battled with the Alliance relief force. Many warships were lost on both sides until the Sith retreated, leaving the planet below devastated.
You will find Han, that often the truth depends on one's own point of view, even Ducato's.
Following the battle Luke called all the Jedi commanders present into the Jedi Council room to tell them what Abeonis had told him beforehand. Many of them, most prominently Han Solo, dismissed this new revelation as a ploy to capture the planet or make conquest of the Alliance easier. Katae-muri however disagreed saying;
"Jasca's a good man who only has the best for the galaxy at his heart. Its only he goes about different means in achieving his aims. Think about it Luke, you once told me that the truth depends greatly on our own points of view. What if; in his point of view, this is the only way to achieve peace?"
At this, all of the Jedi present took a second thought.