Actually, all that info's in the IC already, lists of Null figures and their general behavior, what the various factions are etc.
However, I don't remember it all, can't be bothered to search it when you could do the same thing just as easily and probably get better information for yourself than if I did it(if I remembered I'd just out and say it, though), and don't want to fuck up the names of the groups or something and make the Umbrals out to be bunny-fluffing pet-rescuers.
General gist of it is they hate each other, no way we'll ever convince them to stop, and all in all we're basically little better than resources to them to be used for their schemes, which is rather appropriate since that's rather what we like to think of them as, the only difference being we can't do jack shit to them via getting Essence in exchange for doing stuff and they can do plenty of shit to us via the stuff we just did for them for that Essence which we'll probably have to spend fixing all the things that just broke.
So Fusil definitely has a point in that the Void are terrible and we should avoid them when possible, but they aren't the uber-demons we think of them as; they don't particularly give a shit about us one way or another except so far as it can help them in their goals. If that means we fare better, goody for us. If that means we all die horribly, they could give less of a shit. We're insects in comparison. Useful insects, and insects that might cause a severe allergic reaction when they sting you if you piss them off badly enough, but insects.
At least that's what I know and my working theory, since it means my working plan is to have fuck-all to do with them except making sure they don't screw up my plans, at least until I can reach Stage 2.
I will never reach Stage 2, I'm fairly certain.