Of course power fades just look at the ruins of ancient civilizations and you would be able to notice without a doubt that they were indeed very powerful but they all somehow lost their power somewhere down the road so it is very clear that power does indeed fade sooner or later.
In the Odyssey, Odysseus was the king of Ithaca. He left for the Trojan war, and stayed in war for ten years. After the war, he made to leave for home, anxious to see his wife and son, who he had left as a young baby. Unfortunately he met several obstacles that got in his way of home, including the Cyclops, Circe, and the island of calypso. When he finally arrived home, it had been over 19 years, but he resumed his position right away as king, without doubts that his status had possibly changed.
Every person who has ever been in power will forever have the mindset of a power hungry authority. Anybody who has had a taste of power will strive to get as much as he/she can get. The feeling of control and influence is like a drug to the human mind. It can never be fully detoxed.