Hi gang of Mirror Moon.
I noticed in the recent translation of Fate/hollow ataraxia and saw what caused the back of the Masters and Servants of 5th Holy Grail War back to life was because of a failure in one of the experiments of Tohsaka Rin. The end that goes to the story of Fate/hollow ataraxia is indeed the Fate route. Here are several factors to prove it. Look at all these information:
- Illyasviel are alive on in Fate route (in Unlimited Blade Works route, she is killed by Gilgamesh for having your heart ripped out by Servant and the Heaven's Feel routeâ€™s True End, Illyasviel sacrifices himself to become the Holy Grail, reviving Shirou and seal The Great Grail once and for all).
* At the end of the route Fate (both in the visual novel and anime) is revealed that the Kotomine Church has a new priest (in Unlimited Blade Works and Heavenâ€™s Feel routes it is not mentioned), and in Fate/hollow ataraxia is revealed that the new priest is actually Caren Ortensia (Canon).
* The Tainted Holy Grail (Avenger) was destroyed by Shirou and Saber in Fate route (Canon).
* In the two months before the events of Fate/hollow ataraxia, Rin went to the Einzbern Castle with Illya to do an experiment with a copy of the Jeweled Sword of made by Shirou, to transforms to a pendant and to try to make trips by parallel worlds. The result is that the experiment was a failure and now each and every event in Fuyuki is possible. That's why the Masters and Servants killed on 5th Holy Grail War were revived (except Kirei Kotomine), even with the Holy Grail have been destroyed by Shirou and Saber in the Fate route. So Rin returned to Mage's Association to resume their studies and avoid being punished by changing the dimension of time and space in Fuyuki. She return two months after to the events of Fate/hollow ataraxia (Canon).
* Because of the failure of the experiments of Rin in the castle Einzbern in Fuyuki, all the servants returned not only with the memories they had of the 5th Holy Grail War in Fate route, but also with the memories of the events of the Unlimited Blade Works and Heaven's Feel routes (these two routes are counted as alternate realities). Shirou, Rin, Illya and Sakura as they were the only Masters who survived after the end of the 5th Holy Grail War in Fate route, were also affected and now have the memories of these two routes also as result. That's why Shirou, for example, know about your Reality Marble "Unlimited Blade Works", but can not use it because he could only use this in Reality Marble in Unlimited Blade Works route when Rin transferred his magic seals to Shirou. Or in the case of Sakura, which to discover she has a form created by Matou Zouken (Dark Sakura), she uses this information to transformation to Dark Sakura (but she has control over his actions, unlike of Sakura of Heaven's Feel route) and can harass Zouken and Shinji and so she ends up seizing control of the Matou family. Apparently the masters revived, Shinji and Kuzuki, not have these effects of such accumulation of memories.
And one more thing. I counted the days of the event the 5th Holy Grail War in Fate/stay night, which begin on January 31 until February 15 in the storyline of the game and the days of the loop world of Fate/hollow ataraxia is set in October, during the days to 11. So I conclude that the events of Fate/hollow ataraxia is really pass to more than seven months after the events of Fate/stay night, following the ending of Fate route.