Takato is the inheritor of the first magic
There is only one Anhenerbe cafe' in the whole of the NasuverseThe door you use to leave it determines wheter you get to Kara no Kyoukai's Fumine, Tsukihime's Miyami, Fate/stay night's Fuyuki, the post-apocalyptic Angel Notes setting, or any other future Nasuverse location.
Benedict XVI trained Ciel and KireiHe did use to lead the Supreme Sacred Congregation of the Roman and Universal Inquisition (to use the formal name), A.K.A. the Inquisition (even if it's known as Congregation for the Doctrine of the Faith), for which the Executors work for.
Elaborating on the WMG above: Joseph Ratzinger was an highly successful Executor until he was crippled on the jobAfter being crippled he was made vice president of the University of Regensburg, and then archbishop and cardinal as soon as there was a spot, as a reward for his service, and was later given the job of Prefect of the Congregation because he was the only cardinal who knew what they actually do.
Only one world/timeline gets the "benefit" of the Dark Six awakening ritual. It gets the mana needed by stripping it from other timelines that also do the ritual.The concept of the Jewel Sword; taken to its ultimate conclusion. Fate/EXTRA; possibly Miyu's world in Fate/kaleid liner PRISMA☆ILLYA weren't botched rituals, they just weren't the top dog.