Finally!
Loving each other was the most challenging part -- since your loved ones tend to be unstable and inclined to collapse. This is true especially about Makuria -- they were in collapsing mod for a good 100 years without visible reason -- I sent my Horse Archers to help our African bros -- but they were doing seemingly fine, no threats, no wars, booming economy. Are they scripted to collapse in late 1100s? Tamar was the last one to

me -- the only lady in angry male dominated world of SoI.
Cathedrals: Antioch (late 1000s) -- taken from Rebels, Alexandria (1100s) -- as part of the combined Armenian-Crusader war against Fatimids, Jerusalem (early 1200s) -- sad

by impatient Armenian Royal Saint to speed up Cathedral construction. As a week excuse I must mentioned strange war declaration by PoA which was Orthodox and Friendly

. Right after we finished the phony war with the PoA we decided to punish innocent KoJ. Final Cathedral and victory was gained without backstabing Byzantium -- Rebels conquered Constantinople in 1201 and we just liberated it for the cause of Orthodoxy and used a Great Engineer to speed up the victory.
Overall fun game, took me 4 takes to figure out the right strategy. I kept causing unhappiness in Constantinople with my uber-promoted spy hoping that Byzantium will get a clue and construct a Cathedral -- as a little contribution to the team victory, but they never bothered
Little oddities:
1. Makuria unstable for no reason. They collapsed right after I bribed the last leader to love me.
2. Relics need to be desired by corresponding leaders -- why would Basil decline to trade for the True Cross?
3. If Rebels from 4th crusade manage to take over Constantinople it should get a Catholic religion.
4. F7 screen could show what benefits one gets thanks to the high Piety, like it is done in RFCE (stability bonus, diplo bonus). It really would not be a big deal to get a free Great Saint when players hits a Saint level for the very first time. It's logical, will help Shia URV, and also makes up for the fact that every other Great Person can be acquired via tech -- except for Great Saint.
5. Workers cannot build forts on certain plots, I wonder why...
6. Catholics convert to Orthodoxy way too easy.
7. Strange lack of culture around Makurian city (last attachment)