Reread the whole thing... damn now I sure feel like I left the entire story behind while reading on a monthly basis... what I don't understand now however is why they wanted to seal the sword somewhere else with Maoa's help? Wasn't the original shrine's barrier good enough? Or was it because any normal human could have been asked to take it out?
Yes, once the location had been discovered by the Ghika, they would've had little trouble sending someone to retrieve it and even if Aria's group stayed to prevent it, Ichika would've been targeted as it actually happened.