Power is intoxication. The second strongest one. No doubt, religion remains the strongest intoxication.
Once you taste power, even for a few days, it's hard to get rid of it. Some people earn money and other financial gains through it but there are some people who

Don't want to earn money or anything luxury of that sort.
They just want to have that power. That aroma. That feeling.
They can spend their entire life living in a 10*15 room, surrounded by the mountains of books, few essentials, a packet of cigarettes and a favourite Whisky

Yet, they remain powerful. They can build nations or bring empires on their knees with the help of power.
They are content with the fact that they have power. Power to bring unimaginable changes.

Some people amass wealth through power and they become vulnerable. And at that time, power becomes a means to protect their wealth. Their energy is wasted in thinking about various ways to hide the mountains of wealth they have obtained over the years.

Such people can not bring changes. They remain in constant fear of exposition. They get blackmailed by their own greed. They have a lot of things to loose.
For such people, being powerful means riding a tiger. If they get of that tiger, it will eat them.