Missing for Two Months, I Return as an Immortal Emperor!

Zhang Ning, a high school student who had just been accepted to university, was attacked and sent tumbling off a cliff. To his surprise, he ended up in another world. Three thousand years passed in the blink of an eye. Now an Immortal Emperor in his own realm, Zhang Ning breaks through the void and returns, only to discover that just two months have passed in his original world...