In the event that you or your kin make that daring grasp for power, what do you do with it once you catch it?

We'll define the scope of this question, first. Let's put aside other situations, such as where you and your followers endeavor to remove a tyrannical dictator. Planning and plotting with an agenda to bring about 'a better world' is not where the basis of my question has been formed. In that circumstance, a motivation has already been stoked. We'll also remove the rogue element, a lone gun seeking to wreak havoc. These two situations have motivators, regardless of how moral they are.

Lastly, we'll exclude being among 'the last men standing' following a turbulent war. Those individuals may never have expected to be in power. Only by a slim margin could we expect the original instigators to have survived such an event, an example of which we have recently seen. No, in that circumstance those in power would have a responsibility and the expectation thrust upon them, without ever necessarily anticipating having it.

So that leaves us with an environment where you, with or without followers, have been able to build yourself into a threatening position. It is likely that this happened during a period of calm, and potentially easy going or benevolent leadership. As we have already established, any hostile environment would breed a desire to remove that element from the world. It is also unlikely you could develop such a threatening position in those conditions.

Back to the question at hand. You have the ability to seize power from the controlling faction which has shown no indication they are planning to do the same. This is simply business. Call it expansion, call it a new approach, call it what you will.

Which is exactly what I'd like to hear about, removing the situations we have already discussed, why do we crave power? What do we seek to bring to the world with our leadership, which couldn't have already been done under the reign of the worlds predecessor? Or can we expect that every conflict will be driven by the paranoia of a larger force or naturally cultured disdain for a given bloodline? 

Simply put what could drive a person to remove another group from power, when there is no other external motivator to do so?