A "perfect" score is a very difficult thing to give, especially in this day and age where standards, expectations, and preferences are changing more rapidly than ever before. However I can give Mujun Rasen, the fifth installment of the Kara no Kyoukai film series, a perfect score without regret or doubt.
The film opens in a manner quite different from the style of the earlier movies. Where several of them start with mundane, almost tedious seeming activities and then later build up tension through shocking and/or disturbing turns of events, Mujun Rasen's beginning is heavy on both counts. Fortunately, the steam built up in the opening scenes builds up throughout the film. Although at several point the plot dips to either explain the events that are taking place or for simple character development, much of the nearly two hour production is mystery-solving and adrenaline-packed battles. The movie is even divided (arguably) into 3 acts; All of which are brilliantly connected and have interesting transitions between. Upon reaching the film's finalé, viewers (or at least I) will be on the edge of their seat. Not only does the ending bring great closure, but also a much desired sense of understanding. Which brings us to the next point.
If anything negative can be said about Kara no Kyoukai 5, it is that it is very complex. This is not entirely negative though. Although many viewers will be disoriented by the concepts discussed or even left clueless by the twists, turns, and sucker punches the film takes, it is an inherit trait that makes the film that much more enjoyable. The motives of the antagonists, the explanation of the events given towards the end, and even the conclusion itself are somewhat difficult to piece together, yet this demanding aspect is what makes it a great movie: it manages to make sweat in fear and anticipation, cry, and get the gears in your head turning at a breakneck pace.
As for animation and sound, they don't even deserve mention. This is not because they were poor, but largely because they were so well done I have no way to criticize or analyze them. Ufotable really outdid itself here, and I can say that the Kara no Kyoukai films prior to this one didn't draw near it in production quality.
On a final note: There is no good reason to NOT see Kara no Kyoukai. It is a fantastic franchise and this film in particular is absolutely brilliant. So if you are reading this review after seeing this film at the top of the list for highest ranked anime here, know this: It is ranked as it is with good reason.