と…とても信じられん…こ…この聖域にまでパワーがとどくなんて
Unbelievable! That the power would reach even this sanctuary...!
Looking for an in depth explanation of the usage of とどく; 届く here, because I've read that it means reach as a movement verb that's synonymous with "arrive", and what it means contextually for the subject here "パワー"