Basically, Legion wants to attack to become more powerful than any other. The Dynasty wants to use the energies for the good stuff. And, the Heralds are the mysterious faction who knows everything about energy.
Clans are fighting for it and attacking each other so that they can rule over every other clan. Now, it’s your choice of who you’re going to support. Obviously, the “good guys” is the answer. So, you have to fight and defeat your opponents for the betterment of the world.