There was the two.
Thrilius and Galfor. For millions of years, hate and joy themselves fought and fought. Thrilius tried to keep Galfor in check but, only destruction and fear would follow between the two. Evenually, these fights were getting so bad, Thrilius decided that the ultimate sacrafice must be made. He would be the one to stop Galfor once and for all. He merged himself with Galfor to stop him from doing anything again. However, the merging went a little uhm. Wrong. Galfor was still able to use his powers a little but it wasn't his full potential. But it didn't matter to Thrilius. For Thrillius could use his powers too, to counter Galfor. These powers created two types of human offspring, Peace and Violence. Today, these people still fight each other in wars, in smaller scales than Thrilius and Galfor.