Who or what was Shogun from the early Asia?
"Shogun" was the title held by a military Japanese ruler. The power of the Shogun was sometimes greater than the Emperor, and sometimes lesser, depending on the time in question.
The Shogun never replaced the Emperor in Japanese history. However, there have been instances in Japanese history in which a Shogun exerted quite a bit more influence than an Emperor. Depending on the time period, this was for several different reasons. Overall, the underlying reason for any Shogun to enjoy more power than an Emperor would be due to the fact that a Shogun would have military backing.