[That smile widens to completely absurd proportions and it's clear he's not grinning out of happiness at all. Sadism and madness is the key here.]

Their hearts - the world of their hearts, their home. Take it, and you take their reason for being, the center of their universe. And make them watch as they lose it, unable to stop anything through their own impotence.

But first... Watch them struggle in futility as worlds they're sworn to protect are corrupted and extinguished. With the Unversed as well as the Heartless, it will be easy to do so.