well, the battle against Osmodias and the order could count as a big enough event to call for a long timeskip, after which continuity can be discussed, and the thread move into a new chapter. Character clutter can be removed by some characters simply moving on to a new phase of their lives, old characters can get a bit of a redesign, or new main ones can be found. Abilities and resources are up for evaluation as well, retcons can be found as convenient (like Zhengara not being an actual god, just, dunno, a malevolent spirit or stuff. Supernatural things curse people all the time, or not?
I am all for reviews and reimaginations, though as a total, I am unwilling to just start from scratch. There are character dynamics here that I'd hate to just abandon. For once a game has run long enough that characters pasts actually happened ingame for a good chunk. But first, we need a lonīg break from all the combat, and focus on interactions again more. Perhaps with all the char-deaths from the culling, the other chars simply decided to move on, they might not want this anymore. And with all the terrorism and stuff going on, there may very well be a worldwide crackdown on magic and organisations like IRIS that as a private company still have more money and simply more military power than most nations. Characters might go in hiding, their resources are gone, and they lead a new life now.
It makes for an interesting narrative arc, and a good soil for interaction between characters when then someone stumbles upon plot, feels like something *really* needs to be done, and gathers the PCs he can find to form a counter offensive - and that without massive outside support. Without a deus ex machina to turn to to get everything they need at a moments notice, and that lets them get away with basicaly whatever, it all becomes a whole lot more difficult, and that not just by ramping up power of the enemy