"We need some way to suspend time inside this fortress for one month, and send you off to learn how to do all this in real life, and fail a few times somewhere it's less important than here."
"Failing that, I am telling you now in my capacity as Nethys's chosen one that this is a setup that is inevitably going to explode. Prophecy is broken - for everyone except me, I mean - Nethys can predict events in enough detail to be like, ah, yes, I will do this exact thing, and then Keltham will think this exact thing and react in this exact way. The only way I'd buy this plan is if a god signed off on it."