My only problem is Sil was only recently dragged into the war, so it wouldn't make sense Erian would have established himself this knee deep into Connlaoth nobility if he was using it to go after her. So Erian himself really doesn't make sense to get involved on that large of a scale. Especially since his main thing is collecting magical creatures. If anything, to have it make sense he's there, he could be in cahoots with those on the black market who are taking advantage of helping mages 'escape' Connlaoth and with them, magical beings, etc. But those duping the run aways could be benefiting him and he could be gaining a lot of ground and new creatures during this time.
Does that make sense? lol
Then he could inadvertently find out Silmeria is around and would want to go after her. However, again, I don't know if it would make too much sense for there to be preplanning about what he wants at the moment, since if he is here during the uprising, he'd only find out about Silmeria right now.