By then it is too late for you to do anything interesting, as all your probable and improbable actions have already been taken into account. In fact, you will probably not notice the AGI fooming in such a direct way, and anything you do notice will not be what it seems. The AGI's true goals will likely be completely incomprehensible to us, due to the difference in intelligence level, and something as mundane as removing corruption by overtly killing people seems like an awfully inefficient way of doing it.

In other words, your hypothetical scenario is only good for a Hollywood thriller.