I read to the bit about the "True" Sith, and got irritated, so I decided to write this and skip the remaining 5 pages in the thread...
As far as I can tell, there are (according to Kotor 1 and 2) there are 2 kinds of Sith -
The "True-Sith" - A species that has evolved using the Dark Side to assist with evolution and conquest, and have been doing so for possibly hundreds of thousands of years.
The "Jedi-Sith" - Fallen Jedi that abandon the Light Side and begin abusing the Force for personal gain, power, etc, etc.
Now, the Rakatan race in the original KotOR, being possibly influenced by the "True-Sith", or perhaps have even been subjugated by the "True-Sith" before, decided to use the Dark Side in the same way, conquering most of the Galaxy. In doing so, they left several Trofies on several of there favorite planets, these Trofies being the Starmaps. The Dark Side being ultimatly self-destructive led to the destruction of the Rakatan Empire and (almost) everything they had built. The Starmaps, being severly damaged after the Collapse were lost, but thanks to the advanced technology the Rakatans used, they would slowly rebuild themselves over the course of millenia.
The "Jedi-Sith" Empire was founded by renegade Jedi. They owned a small area of the galaxy and made their Capital Planet Korriban. While on Korriban, they discovered the Rakatan Starmap. Not knowing what it did, Naga Sadow took it as a trofy and had it placed in his Tomb when he died.
The Rakatans discovered Korriban and found to be a barren and desolate world, but since it was powerfully tainted the the Dark Side they stayed and left a Starmap there. The Rakatans were unaware that Korriban had once belonged to the "True-Sith" Empire but had been abandoned/left/unused by the "True-Sith" Empire several thousand years previously.
The "True-Sith" have had an Empire for hundereds and thousands of years. Korriban, Malachor 5 and Dantooine were on the extreme edge of the space they controlled, but because of some reason or another Dantooine and Korriban were either abandoned by them or taken forcibly by the Rakatan. The Trayus core, being an outpost and beacon for the "True-Sith", had then "up-to-date" records of known space and teaching methods, including information of the Rakatan Empire and the Rakatan occupation of several of the "True-Sith"s abandoned planets (Korriban and Dantooine among others). They later abandoned Malachor 5 aswell.
Revan, ignoring the will of the Jedi council went to war with Malak and those that wanted to come with. While leading the Republic fleet Revan made a plan that could change the direction of the war in a single battle, and after learning that Malachor 5 was taboo to the Mandalorians, decided to visit the planet and check it out. The first thing Revan noticed when he stepped on to the barren, rocky landscape was the taint of the Dark Side. After possibly a few weeks searching Revan found the abandoned Trayus Academy and Core. As Revan was still loyal to the light side at this point he/she decided to explore the Academy and find the source of the taint. He/she stumbled upon the Trayus Core. After a little more searching, he/she found the Academy's Library and Data stores. Revan, intregued by the wealth of information he found spent several days there absorbing as much information about this elusive "True-Sith" Empire. It was here he learned that the Madalorian War was a cover, an attempt to destabilise the galaxy enough to make conquest as easy for them as possible. The "True-Sith" were planning on destroying the Republic and placing the entire galaxy in chains. He felt that it was his responsibility to protect the galaxy and searched through the Trayus Library for anything that could help him. He stumbled apon information about the Rakatan Empire and there crowning glory, the Star Forge. He didn't know what is was, but any help was better than none. He learned from the decaying records that the Rakatan Trofy Worlds held the maps to the Star Forge, but the records were so badly decayed he only managed to get the coordinates to one of them. It turned out to be Dantooine. He had learned from the records that the Rakatan Empire used the Dark Side of the Force and he remembered that close by the Jedi Academy was an Ancient Ruin that eminated the Dark Side taint. He traveled there together with Malak and found the Star Map. Revan knew that he may fall to the Dark Side during his crusade but he believed the coming invasion by the "True-Sith" would bring more destuction in a few months than he ever could in his lifetime. It was a risk he was willing to take. From the Dantooine Star-map, he learned the locations of the remaining Star-Maps and found the Star Forge. He recognised that the Star-Forge was a massive factory that could help him repel the "True-Sith" invasion, but he only had the reminents of the republic fleet to man the ships the Star Forge was crurning out. He didn't have the forces required. He turned the Star-Forge on and left it running while he took care of the Mandolorians. He resoned that he would need as many Jedi as possible to win the impending war against the "True-Sith", but only Jedi that would be willing to die for him. He set up the Ambush at Malachor 5 and the Mass Shadow Generator made. The combination of the Dark Side taint of the Trayus Core and the Massive slaughter of both Mandalorians and Republic Soldiers alike, those that were strong enough were turned to the Dark Side. The rest died (Except the Exile). Revan was now "Jedi-Sith." He still believed that the impending invasion was priority No.1, but the Republic was weak and broken, even though the Mandalorian threat has been eliminated, they has still done what they were supposed to do, soften the republic. Revan knew this and saw that the republic would not recover quickly enough, so he decided to take control over it, to solidify it and prepare for the invasion. He took the remains of his converted armada to the Star Forge, placed them in new ships and started to take the republic over. Those that didn't surrender willingly were made to surrender. He founded the Sith Academy on Korriban to train effective warriors for the coming storm. He knew he had fallen by now, he had known since Malachor, and his new philosofy on the coming war was to "fight fire with fire", "Jedi-Sith" against "True-Sith", it was there only chance he thought. He was then captured by the Jedi and had his memory erased. Unknowing of impending the "True-Sith" invasion, Malak was a true beliver in the "Jedi-Sith" way, and used the armada for personal conquest. He wanted to control th Galaxy. Where Revan had thought his fall to the Dark Side as necessary to ultimatly protect the galaxy, Malak revelled in the Dark Side and sought nothing more than destruction for anything that opposed him. Revan, given a second chance removes Malak from power eventually. Remembering new things about his former life, he eventually remembers the "True-Sith" invasion. He leaves the galaxy to try and stop the invasion before it starts, leaving everything behind, he heads into the unknown.
There.
Done.
At last(!)
Many of the connections I've written about here are probably wrong, but this was the impression I got when I completed both games. Hope it helps!
