The evolution of J10C to the J10NG (Next Generation) would have to have upgrade on
1) More powerful engine
2) Electronics specs on the level of J20 where space and power generation permit
3) LO stealth, probably including canted V tails
4) Concealed weapon stores
5) Probably larger fuselage to accommodate more fuel and thus larger combat range (eg. F/A-18 Hornet's evolution to larger Super Hornet).
6) Air intake changed from chin location to sides, so as to provide space for concealed weapon store as well as S shape air intake duct for better stealth. (refer nose air intake J8 to side air intake J8A as precedence).
(1), (2) and (3) above are almost a certainty except the canted V tails, (4), (5) and (6) are speculative (my 2 cents).