If you're somehow taking energy out of the Big Bang, you're probably responsible for starting that event, as you're disrupting the perfect balance that kept everything in a minimum-entropy singularity. Introducing it again much later in the past might be enough to close the universe again and eventually induce the Big Crunch.

So, mazel tov! You're repsonsible for both the creation, and the destruction, of the entire universe! We hope you're happy.