Starwing's theory about why the Shivans do what they do:
I can see the holes myself, but I still like it, somehow.
The Shivans where created by another race, let's call them Titans
(fathers of the gods
) They built them to guard their borders, which are, in space, subspace nodes.
Over time, the Titans developed, and with them also the Shivans. One sunny day, the Titans started to fear their own creations, because they had grown too strong. So they tried to wipe them out. But the Shivans didn't let the Titans wipe them out. They fought back and retreated into the nebula. This was the beginning of a war between Titans and Shivans. But over time the Titans grew more powerful than the Shivans because Shivans are warriors, they are not able to develope themselves. So they started to raid other races. For example: Ancients where experts of subspace physics, as they built the Knossos gates. Shivans came and wiped them out and got hold of the advanced subspace technology.
And they did another thing: playing god. They pop up with a almost unstoppable force and force other races to evolve to be able to stop this force, then the Shivans steal the technology the other race developed. Like: Titans have unbeatable shielded ships, so Shivans go after ancients with Lucy to force them to find a way how to kill Lucy. They didn't find it in time, so Shivans come back and attack Terrans. Lucy is killed, and while the fleet distracts the Terrans the Shivans take subspace tracking device to kill Titans.
They also present their technology to the Terrans: shields, beams, and so on. Years later they return to look if their seed has grown. It has, as Terrans now have beam weapons. They take whatever they could use (probably advanced Vasudan reactor cores?) and present another piece of tech, the supernova weapon.
You guys are still