Board Thread:Questions and Answers/@comment-177.143.84.148-20160110023317/@comment-25121259-20160111201502

It's not Takamagahara, it's Amaterasu that does it. As to why, it's most likely to complete the "story". Also, from the looks of it, the loop is not the "story", although the loops are part of the "story".

As to why the loop is necessary to complete it, basing on what was shown, it's because:

a) the Hero is the one that kills the Monster,

b) one part of the Hero can kill only one part of the Monster,

c) an ex-hero can't kill the Monster again (in other words, one part can only kill one part and only once).

a) is stated in the "story";

b) is shown through Bloodedge and Hakumon each killing one part of the Monster during Dark War, as well in how Jin (without the other hero part) was enough to kill the Black Beast when it was only made of Ragna (in CS);

c) is shown through Hakumen never killing the Monster, or part of it, again:

- when he defeats both Ragna and Nu in CT (one of the timelines), he doesn't kill them but simply throws them into the boundary separately,

- when only Ragna turns into Black Beast in CS (one of the possible outcomes), he doesn't participate in it's subjugation (neither does Jubei or Noel for that matter),

- even when he shows the desire to hunt down one of the parts, he is always somehow stopped (like in CP), or decides to postpone it (like in CS) or decides to do something else (like in CT).

Well. as stated, the "book" already got worn out, so the current story being quite far from it's initial version isn't such a strange thing, although the initial fixed values have remained.

Also, in the case of Ragna already being considered as an ex-hero, it would mean that, even if he wanted to, he wouldn't be able to kill part of the Monster again, thus in a sense opening path for another possibility, specifically for the "desired" outcome (which could have been considered impossible without Ragna first becoming an ex-hero... from the looks of it, that is).