If the J-20 meets its 2017-2018 IOC target date, it will give China a technological edge in air to air combat over all its Asian neighbors, who do not yet have 5th generation planes. As a heavyweight stealth fighter, it is armed with long range missiles, electronic warfare, advanced radar and passive sensors, making it a respectable competitor to even the new US F-22 and F-35 stealth fighters. CAC is already planning a series of future updates to keep the J-20 state of art; domestic WS-15 engines are just one of them.
The J-20 will be stealthy, fast, heavily armed with long range air to air missiles, and state of the art radar and infrared sensors. Perhaps more than any other weapon, the J-20 represents China's military modernization. via China Defense Forum
Also Improved J-31 fighter
China's second fifth generation fighter, the J-31 is a twin engine, medium weight stealth fighter built by the Shenyang Aircraft Corporation. It is undergoing testing, while waiting for firm domestic and export orders. A display floor model of an improved J-31, with a larger fuselage, improved indigenous engines, stealthier features and improved sensors, was prominently displayed at the Zhuhai 2014 Airshow. The second J-31 prototype, incorporating those improvements, is expected to make its first flight soon, if it already hasn't done so. A first flight of the improved J-31, just in time for the 2016 Zhuhair Airshow, would greatly improve its sales prospects at home and aboard.
As Chinese defense exports grow, the J-20 and J-31 could start making the rounds at foreign airshows, and possibly even in foreign air forces.
SOURCES- Popular Science, China Defense Forum, mil.qq.com