This is suitably calm for a death scene. My concern is maybe it should sound graver and sadder a little when she is stumbling to her knees in the first few seconds, I got this impression there were kind of four, five distinct stages to the video, like Xion vitally communicating instructions etc before she passes, etc. That was the only thing was it was a little too uniform without some ups/downs for the segments.
That said, I thoroughly enjoyed it.