Ummm... Doesn't spread? Mictlan God, and their temples don't spread dominion, but Blood Sacrifices do, and I think prophets and juggernaughts do. I'm not sure if their capitol does. Mictlan probably wont be winning through dominion killing, but blood sacrificing is powerful enough to make your dominion 'safe' from enemy dominion, and to get your scale benefits (except perhaps buggy growth 3
) I certainly find that I can do ok in dominion terms, and I think thats a fairly common sentiment, though if victory was set to dominion I probably wouldn't play Mictlan.