Missing Piece of the Heart

Humans went extinct hundreds of years ago after the final war between the hybrids who fought for their freedom, and the humans who wanted to enslave and control the hybrids. The war ended with death and bloodshed from both sides, the hybrids however came out victorious.
With the humans gone hybrids were finally able to live in freedom, as society continued to evolve so did the hybrids.
However as the main threat was taken care of, a new problem for hybrids appeared. In the current day and age, certain hybrids began targeting the more rare and favored breeds. All hybrids have mates, it can range from 1 mate to 10 and possibly more. Hybrids who had no interest in finding their mate(s), rejected them, or got rejected started hunting and kidnapping certain breeds in order to have strong, rare, and exotic offspring, and sometimes just for their own greed.
Because of this, it has become dangerous for unmated hybrids (as they are more likely to be targeted).