Hmm, unfortunate if he's out then.
I originally liberated his lands from the giants(if I had known he'd go away, I'd have kept them and taken the rest of his stuff) since their guys are much better than me against Ermor. I even gave him fire and earth gems in the dozens since I couldn't use them that well.
Although if he was a secret ally of Ermor at the same time, I guess it might have been pointless anyway?
If Ulm does get a new player, he obviously wouldn't be indebted to me for freeing his lands, so it's not that useful overall. The AI might be better if they recklessly attack Ermor, since I'd assume a human Ulm replacement would be very careful, even though it'd be in his best interest to squash Ermor with me and gain some land.
I'll advertise a bit, but if it looks like no one bites, we'll have to AI him.