One word summary of race: Evil. The Ori are also an old race, but it is thier unique ideals that really separate them. They value control, view themselves as superior, and have no concept of mercy, patience or tolerance. In short - they are evil dominators, who use whatever methods they see fit to accomplish their goals. And those goals are domination of the known planes of existence. You will find most of the Ori come from past races such as the Goa'uld, Ashen, Eurondans, the Wraith or even the most advanced of the Replicators'(yes - they overcame the limitations of 'soul energy' through energy manipulation, and a few ascended instead of perished.) These beings are strong, and focused on conquest. They sacrifice energy harmony with the environment around them, and also do not value internal growth. They are therefore slower to grow personally, although most adept at taking what they want.