The Cydans are a very advanced species; take for instance a Vasudan and multiply it by 15. Thats how advanced the Cyands are. The war between the Cydans and Shivans is nearly 10,000 years in the making. The Cydans travelled and conquered, not unlike the Ancients, and they were the first of the two species (Ancients and Cydans) to be resisted by the Shivans. The war between the Shivans and the Cydans started about 10,000 years before the Great Wars between the GTVA and the Shivans. The Cydans resisted the Shivans for 2,000 years, but because the Shivans had held the Cydans to their home system for 2,000 years, they were not travelling in subspace, wheras the Ancients were in the Altair system and the systems surrounding. The Shivans broke off their attacks on the Cydans to attack the Ancients, thus leaving the Cydans for another 8,000 years, mostly forgetting about them. This gave the Cydans time to retreat and regroup and again rebuild their once great armadas.
This is all I am really going to tell. I might edit some places here and there in the story, but in all essence, the Cydans are the arch-enemy of the Shivans, and nothing will stand in their way, not even the GTVA. You'll need to kick your butt and start moving in my campaign, because fun wont stop, but this is if I get my campaign and a web site. BTW, the Cydans are also out for some more conquering......