Power does not create character; it removes certain reasons to hide it.

Character is mostly formed elsewhere and then either restrained or released by circumstance. When you gain power, the incentives that kept certain impulses in check quietly disappear, and what surfaces was already present, previously held down by the need to be liked or the fear of consequence. Nothing new was created.

If you have gained any authority recently, ask what you now do that you would not have done a year ago. That difference is worth examining while it is still small enough to reverse.