Doesn't that kind of reinforce the stereotype though?
1. They are patient. If a plan takes tens of thousands of years to come to fruition, they are perfectly willing to wait. See the first conquest of Toria as an example. The Yor are probably the only race more patient than the Drengin.
They are long term thinkers. I think that in our fast paced modern society, long term thinking has been forgotten. I do find that whatever their other flaws, East Asian societies tend to be better at this. Being patient is not as alien as it seems.
2. They are calculating. When the Drengin gained access to Hyperdrive they could have easily re-conquered Toria. They didn't, because there was no point to it. They had already strip-mined the planet of all valuable resources. If the Torians hadn't antagonised the Drengin at every possible opportunity, the Drengin would have most likely ignored them. However, that wasn't meant to be. Now, the Torians serve as dinner.
Isn't that common sense? Only conquer what is worth taking?
3. They live for conquest and slaughter. Citizens happily give up personal agendas, if it will make the Drengin more lethal.
Again, in more collectivist societies around the world, that is very common. The individual's needs are always subordinate to those of the collective good.
4. They are telepathic. The Drengin can sense pain and anguish, and are absolutely ecstatic about experiencing it in others. They're don't like experiencing pain themselves, however. (Except for the researchers. Pain makes them think better.)
The fact that they are telepathic appears to be amoral. But their blind love of pain seems to fit the "stereotypical evil".
5. They don't understand fiction. For the Drengin there are truths and there are lies. There is no make-believe. There are no fictional books or actors in Drengin-society. The Drengin are not entertained by such things.
In a sense, they don't have a culture here - no stories, probably limited art too.
6. They do what they're told. If you have a genetic pre-disposition towards research, you'll become a researcher. If you have a genetic pre-disposition towards combat, you'll become a warrior. If you have a genetic pre-disposition towards dying a painful and horrible death, you'll die a painful and horrible death.
Again, collective society mentality. Individual is always subordinate to the collective good.
7. They're great genetic engineers. Over the millennia, they learned how to grow better and better researchers, slaves, and warriors. A little too good in case of the Korath.
8. They're slavers. Do I even have to go into this?
I've probably forgotten a couple things. However, I know more about the Drengin than about the Meklar (or any of the other races) from MoO 2, and I've played MoO 2 long before I've encountered GalCiv.
I think this reinforces what I've said. They will use genetic engineering where it suits their needs.
From this we can presume:
1. They are very collectivist
2. They are very long term thinkers
1&2 are common throughout many societies on earth.
3. They are very practical, using whatever tools and technologies (hyperdrive, genetic modification) as they see fit.
4. They desire dominion over other races.
5. There's a certain pragmatism - only conquer what is worth taking that goes through their society.
6. Society is probably very meritocratic.
There's no underlying culture in a sense.
It's very:
"Hello. We're Drengin. We just want to conquer the universe and enslave anybody. We're quite pragmatic and know that this could take some time to do. The end."