I've got specific events mapped out by relative time. What you do in between those events is up to you. I scripted the appearance of a horde- I did not expect people to run into the bulk of the horde. I had planned on the dark esper appearing, I however leave the party in charge of what happens from there. I will say that the parties actions have negated on event that would've made this engagement easier- and I think I've hinted to that enough >.>