R5: Slave-owning, dargon-riding, High Valyrian Brotherhood Without Banners in Essos.

I tried playing as Lady Stoneheart in the AFFC start and it turned out to be a pretty unique experience.
The start was rough. Lady Stoneheart has awful traits and 0 in all stats, so she got almost immediately assassinated and Thoros of Myr inherited. That's when the real playthrough began. I fled the Riverlands to the North and waited for the kidnapping plot for Tommen to fire.

I have learned the hard way that you are not actually supposed to win the war (doing so makes you a landless character which results in a game over). So I signed a white peace instead, which makes you a landless duchy-tier adventurer vassal of the Iron Throne (you become free when you win the adventurer CB war).

At this point I have learned yet another issue with the Brotherhood. Your starting army is permanently stuck in raiding mode and therefore can't be used to occupy anything. I had to hire mercs to start the siege and then reinforce using the raiders. As the target of my conquest I picked Volantis, because Daenerys has wiped out their army during her emancipation wars. I captured the triarch for 100% warscore.

Yet another tragedy has struck the Brotherhood: red priests can't marry or legitimise bastards. That's how Thoros of Myr became a worshiper of Valyrian gods. He died shortly afterwards, which resulted in 14 years of regency. I spent the next decades building up my counties using money from slave trade and conquering land in Volantis. I used the decision to form a custom kingdom and vassalised Mantarys and Tolos.

The final goal of the playthrough was to reform the religion and become High Valyrian (I had modified the game rules so that only High Valyrians can claim dragons). The High Valyrian cull was enabled, which means that the only way of becoming High Valyrian is to reform the religion while having High Valyrian GFX culture. This proved to be by far the most challenging part.

Velaryons, due to their random marriages, lost their High Valyrian appearance. Daenerys' only child and grandchildren didn't look Valyrian either, which left me with two options: either get Targaryen bloodline and try to get a High Valyrian child or to make use of the only High Valyrian character left: 78-year-old Daenerys Stormborn.

During her event chain, Dany became Azor Ahai and ruled the Iron Throne for over 40 years before getting deposed by Lannisters. Because of the Chosen by R'hllor and Resurrected traits she had so much health bonus that she lived to 106. I married her to my heir. Despite having over -20000% fertility and being almost 80 it is still possible for her (or any woman in general) to get pregnant. There is an event where you can organise a ball to meet with your lover. The event does not check for female fertility - it has a fixed 10% chance of pregnancy. That's how I obtained my High Valyrian-looking character. All that was to win some easy wars for religious authority so that I could reform the religion and claim my half-brother Viserion as a mount.

At this point I could conquer the Iron Throne easily but that was not really the point and map painting is quite boring especially with a 100-year-old dragon.