It's not one. ... After I revived her, she... left. She didn't like that I'd used the lives of so many Pokemon to revive her. ... And I don't blame her now.

... But then, I was angry. Angry at her, angry at the war that had first taken her from me... and so I reversed its function. I used the leftover power and fired it at the battling armies. The war ended, but so did many lives, and Kalos as a result has had... fewer native Pokemon species than other regions.