The planet Nibiru was an extremely energy rich planet, causing it to develop a vibrant and diversely populated world. Not only were tens of millions of different species of beasts found in this world, but they also had incredible strength.
An unexpected result of this, however, was that it became an extremely chaotic planet. Battles happened night and day, and only a few overlords who could control large regions of space managed to bring some semblance of calm to their lands - if they chose to do so.