Title say it all. I never understood why Xehanort would do that - yes, he counted on Aqua catching her friend but he couldn't be sure of that and in the worst case, we would've had Ventus scattered all over the place so no x-blade for him. It seriously looks damn cool and dramatic and stuff, but for a calculating man like Xehanort, wasn't this kinda reckless? I know he wanted to "fuel the anger" in Terra but he was already pissed enough having been tricked into the master-killing scheme and harassing Ventus so no real need for that. What would he have done if Ventus had shattered?