Episode 7 - A better love story than Twilight
Damn a whole week has gone by. But I simply didn't have the time to sit and watch this unfortunatley until now.
Also RIP Kokuto's eye, this movie was definitely better as a second viewing. I could take in quite a lot more and I appreciate how everything came to a head. One of Nasu's strength's as a writer really shows in this movie, he can take a simple concept and spin it quite far in so many different ways. And even after death Araya's influence is still felt.
So lore time
The origin is explored a bit in this movie, and explained really well by Touko. As a brief recap, as people die they become worm food, then that food becomes the grass, eaten by other animals passing your soul through a reincarnation cycle similar to Buddism. The moment your soul came into existence as whatever it was at first is what is referred to as your origin. Everyone has an origin, magus or not, that determines how someone will act in their everyday life. Our serial killer's origin is "Devourer" probably from being a Lion, Kokuto's would be something like "pacifist" which probably came from being a sheep. In Fate, Emiya Shirou's origin is "Sword" as noted by Tohsaka.
Araya was a magus who specialised in bringing out a persons origin as he mentioned in movie 5. Normally an origin's effect on a person is something as minor as he's a nice guy, or he's scared of spiders. It's when a person becomes accutely aware of what their origin is, that is when it becomes twisted like our serial killer in this movie. He had the origin "devourer" so when he became aware of this, that is what he must do and can no longer be swayed. While a person is unaware, eh it's more like a mild suggestion and you still have control.
The origin of a person is also a persons tie to the root, it's how the planet controls guides people so they don't do something stupid like say... try to reach the root. This also has the effect of allowing the counter force to directly tap into a persons origin and guide them away from doing such a silly thing.
As an aside Mages are simply folk who have become a bit more aware of all this, and have made it their ultimate goal to reach the root and gain such power. I bring this up as this should help explain the level of difficulty that a magus will face in the nasuverse. When your opponent is an all omnipotent power such as that, oh and other mages. Plans to reach this goal are thought up over generations, and executed over generations more. Hence why passing on your magic circuit is of utmost importance in magus families.
Speaking of mages, they are taught about the origin as part of their training. This is because the origin also determines what type of magic that person will be good at. Makes sense doesn't it? In real life a person with an interest in computer's will more than likely train to be a coder or an engineer. Same for a mage, someone interested in geology might studie earth magics or something to that effect. If a magus can read your origin they can make a solid guess as to what spells you have up your sleeve.
A second positive effect of studying the origin for a mage is via the magic circuit. Mages study and perfect a single magic over their life, this is then written on the families magic crest, and passed on from mage to pupil who then has access to that, and will also proceed to expand the family crest with another magic. So basically choosing the right pupil to make a better crest is an important part of the selection process. This is why mage society has a heirarchy where older mage families have more prestige, it's simply because they were around longer and have better magic crests.
Well anyway TL;DR - Araya sucks and was too dangerous to let live.