Who is the guy who gave the Emperor of Japan the advice to be optimistic and that everything would turn out right in the end?
The Japanese emperor is supposed to have come from the heavens, so that just makes this heaven emperor the emperor of Japan.
This is a jukugo word that uses the on'yomi readings of the kanji. You just have to remember that 皇 is read as のう here. You just found out you can never be the Emperor of Japan because you aren't Japanese. NOOOOOOOOOOOOO~ (のう).