I have played the scenario as Calabim earlier. So I choose to play with Malakim this time.
I play the scenario with Tholals more naval AI. It seemed easy, did I really play on emperor.
Found the mirror of heaven after a while then Calabim declared war on me. I attacked him with my Decius camel archer. Raced one city then pillaging all improvement on the other cities.
Trading alot of tech to make people like me to get open borders. Then gave away honor and upgraded my lightbringers to spread my religion. By the time the 75 turns had gone I had spread it to all except some barbarian cities and the dwarfs. Was at about 70%. Me, Malakim, Calabim and Elohim was Empyrean.
Then I started to use my inquisition on my allies towns. After a while I was able to get open borders with Calabim and sent my inquisition there as well. It was really on the Kazad that was slowing down my victory. Perhaps I should have marched my army there earlier instead of trying to get open borders with him.
I noticed that you can't remove religion from holy cities. Had a skirmish with Svartalfar and made them change to Empyrean but was unable to remove the holy city so they changed back after 10 turns. But it was enough for me to clean their cities of other religions. So my advice is to raze holy cities as often as you can. And if you found extra religions starve those cities to prevent it from having impact.
I'm happy with the scenario. I manage to get all nations to join the overcouncil, all except the dwarfs to adopt Empyrean. And somewhat peaceful as well. Calabim lost a city early, Elohim lost a city to Malakim.