Greatest Boss System summary: You are reading Greatest Boss System manga, one of the most popular manga covering in Action, Adventure, Fantasy genres, written by Feng Qi Yue at MangaBuddy, a top manga site to offering for free. Greatest Boss System has 185 translated chapters and translations of other chapters are in progress. Lets enjoy. If you want to get the updates about latest chapters, lets create an account and add Greatest Boss System to your bookmark. Who is he? Why is he called the Boss? Maybe he's the fearless ruler of the world. Or maybe the worst enemy of humanity, who tears worlds down. After Su Sin was reborn, he lost all his skills and abilities from former life in a knights' world. However, a newly implanted System can help him restore them. "My name is Su Sin where Sin means Promise keeper".