Ok. Here are my thoughts. Jess, you wanted the plot to be primarily the responsibility of you and me, so I'm taking it on. Here goes.
First, the weakness--the only weakness that makes sense to me is love or any of those positive attributes related to love. it is the one thing that, in canon, JK Rowling referred to as the oldest sort of magic. It was the one thing Voldemort could neither understand nor overcome. I think we have set the plot up to go that way from the beginning. I think to do less now is backpeddling too much.
I think we need to escalate both the attacks on individuals and on groups. We need to increase how often we do that. Not the severity. Just the number of attacks. We do not always need to kill. Injuries are good. Not just physical but also emotional or mental damage. Trauma. What about destruction of buildings, streets, or anything that the demons would think that humans would see as being significant to them? The creation of just general chaos is always a good thing. In my thinking, this should be a rather continuous thing until we rid ourselves of the demons.
We need for members to start to come together to try to decide what to do with them. Meetings with faction leaders deciding on at least a temporary alliance. I would like to see a meeting of all faction leaders sometime around the end of September or first part of October, with faction meetings following that to relay information from the meeting of the leaders. The announcement of the alliance should come sometime after that, and they should be working first on discovering how to drive the demons back. At some point, they need to realize they cannot kill an immortal--they can only drive them out of their realm. I'm thinking that we need to do the meeting of the faction leaders sometime in Late september or early october, with faction meetings happening right after that.
As the attacks continue, members need to see that it is not the patronus that drives the demons away but rather the members' control of positive values and how that power of "old magic" increases when the members increase in number and use that to defend themselves. It seems to me that this has to work similarly to the mindset needed to cast a patronus, also with Occlumency built in so that the demons cannot wipe all the love and positive attributes away from the characters who are standing against them. Might have to be a specially written spell, maybe by a consortium of our Tier 2 characters. This, ideally would happen in early november-ish.
Eventually, I think we need them to make a stand against the demons that drives them back into the portal. once the last demon is driven back through the portal, the portal should just close up and disappear on its own. I would like to see this happen in early to mid December.
I'd like to see this whole business wound up and have us moving back to a decidedly more HP direction by no later than Christmas if not before. Remember, all, we're only looking at a little more than 3 months away.
I'd like to see us coming up with a new plotline by then and be putting the foundations of that in place before we off the demons entirely.
Next point--And, sorry if this rattles a cage or two, but can we please have our next plot idea in the planning stages so that we can be weaving the beginnings of it into the ending of the demon plot? I really don't want to see us going without a significant plot again. I think that's illadvised for the site as a whole.
IF THIS IS THE GENERAL DIRECTION WE WANT TO GO, THEN SPEAK UP. I'LL WORK ON MAPPING OUT MORE SPECIFICALLY.