I have been scouting Abysia quite a bit and his power is quite formidable. They have massive flying demon armies and bloodhunters in almost every province. But yea, because of the game rules punishing turtling, it is highly improbable that he will be able to win. The only way for him to win would be to somehow transport armies to the other side of the map to take Caelum/Midgards capitols.
In fact I think he realize this himself. You notice that he is not trying to siege your capitol? He is just building forts. Why is that? Its because of Mictlan. If Mictlan takes either Midgard or Caelum, and Abyssia takes Utgård then Mictlan has won. There would not be enough victory points left for anyone to get more of them than Mictlan.
As for mictlan, I thought his tactics strange for a while. Why did he not pursue blood more throughly? But then I realized his plan was to take Midgard/Caelum before anyone could think to stop him and that he was sacrificing future power to win in the present. This plan failed, but only barely. Caelum sure got a nice show. And what ever is up with Mictlan stealing my shoes. Who'd steal a dead mans favorite shoes anyway.
We could ignore the victory conditions and I could have a showdown with Aby. I have certainly been planning and building for such a war. But the Late Game is the least fun part of dominions imho. And it is doubly boring if you dont have any chance of winning. I would understand if no one else wanted to sit around and watch from the sidelines.
Weather this game is over is up to you guys.