TLDR: Only natural born demon spawn can get "Birthright" not demon spawn from a satanist's "dark impregnation" power.
I started my current game as Duchess Matilda di Canossa of Tuscany in 1066. Achievement goals were:
Survivor Black Bishop Black Pope Dark Lord Birthright
As my first ruler, I become queen of Italy. On my next ruler I became independent from the HRE (because I don't want to be burned at the stake when I become a satanist). I work my way up to cult leader and get the "Dark Lord" achievement. While doing that, I also corrupted the pope's heir and got the "Black Pope" achievement when he inherited.
So I'm all set to get myself a demon child so I can get "Birthright". Turns out dark impregnation can only be used on yourself or the target of a mission. I kill my children and make sure that a daughter inherits.
As my third ruler I worked myself up to leader of the satanists again. I used dark impregnation on myself and got myself a demon child. I made sure I got the depressed trait and committed suicide before he grew up.
So I'm on my demon child 4th ruler. He turns 16 and I'm waiting for the achievement to pop. Nothing happens. I use ironmelt to hack an old save and made sure I'm a demon child. Finally I check the code to see how this works.
The demon spawn from using the satanists' power gets the flag demon_child or demon_child_fake. Old Gods event TOG.3260 immediately gets rid of these flags as soon as the child becomes 16, but that's not important. The Sons of Abraham event SoA.3020 is the one that sets the demon child as the leader of the satanists. But the demon child must have the flag demon_child_non_pagan which is only give to natural born demon spawn.
EDIT: Checked achievement_events.txt and apparently becoming leader of the satanists with demon_child flag is fine too, but the problem is you have no time to do it when TOG.3260 immediately clears that flag when you turn 16 (even before you can join the society).
I disabled the Old Gods DLC and loaded up a save before my demon child grew up. Then I joined the satanists and ranked up the old fashioned way. Got the achievement when I became cult leader.
EDIT: I just got the "Black Bishop" achievement and wanted to share but didn't want to create a new thread for it. Basically I decided to throw away my game (not really, I made a back-up save). I invited a landless courtier who already had the wicked priest trait.
I already had a cardinal who wasn't a wicked priest. I imprisoned and executed him, freeing up a spot in the College of Cardinals. Then I revoked all the bishoprics and either granted independence to all my vassals or put them in revolt.
Next I gave one of the bishoprics to the wicked priest, so that he was the only candidate I can support for the open spot in the College of Cardinals. I threw 2000 gold into his election. Once he got elected, I set him up as an antipope and pressed his claim.
Okay, I know what was the problem. It's just my old save (from the previous DLC) and just apparently achievements from a new DLC don't work on an old save.
So the trick to getting this is using unholy impregnation on your female character, then once your satanic child is born, disable the Old Gods DLC before he/she turns 16?
There are two types of demon children: the ones you get from using unholy impregnation and the ones that go around killing their siblings as children.
The ones who go around killing their siblings become leader of the Satanists (unlocking "Birthright" achievement) as soon as they turn 16.
The ones you get from unholy impregnation needs to rank up to leader the old-fashioned way, and you need to have Old Gods DLC off the whole time before you unlock the "Birthright" achievement.
Interesting, I would have never thought that the Old Gods DLC meddled in such a way in a feature of Monks and Mystics. Thanks very much for the info!
In order to get this using the "Unholy Impregnation" way, do you need to have the Old Gods disabled for the entire campaign, or do you have to disable it only after the child is born?
Also, if you need any help regarding any other achievement, feel free to ask. I have every single one except the birthright one...and it's been driving me crazy!!
In order to get this using the "Unholy Impregnation" way, do you need to have the Old Gods disabled for the entire campaign, or do you have to disable it only after the child is born?
Disable it any time before the child turns 16.
Remember that "Unholy Impregnation" has an equal chance of giving a child with demon_child and demon_child_fake. The Birthright achievement only fires if you become the cult leader with demon_child or demon_child_non_pagan. (Natural born demon spawn have demon_child_non_pagan.)
I'm sure that this problem from The Old Gods DLC is probably some code that existed before M&M was released. I can't think of why they would deliberately make such a mess otherwise. I'd report this as a bug, but I'm too lazy.
I disabled the Old Gods DLC and loaded up a save before my demon child grew up. Then I joined the satanists and ranked up the old fashioned way. Got the achievement when I became cult leader.
EDIT: I just got the "Black Bishop" achievement and wanted to share but didn't want to create a new thread for it. Basically I decided to throw away my game (not really, I made a back-up save). I invited a landless courtier who already had the wicked priest trait.
I already had a cardinal who wasn't a wicked priest. I imprisoned and executed him, freeing up a spot in the College of Cardinals. Then I revoked all the bishoprics and either granted independence to all my vassals or put them in revolt.
Next I gave one of the bishoprics to the wicked priest, so that he was the only candidate I can support for the open spot in the College of Cardinals. I threw 2000 gold into his election.
Once he got elected, I set him up as an antipope and pressed his claim.
Achievement unlocked.
There are two types of demon children: the ones you get from using unholy impregnation and the ones that go around killing their siblings as children.
The ones who go around killing their siblings become leader of the Satanists (unlocking "Birthright" achievement) as soon as they turn 16.
The ones you get from unholy impregnation needs to rank up to leader the old-fashioned way, and you need to have Old Gods DLC off the whole time before you unlock the "Birthright" achievement.
In order to get this using the "Unholy Impregnation" way, do you need to have the Old Gods disabled for the entire campaign, or do you have to disable it only after the child is born?
Also, if you need any help regarding any other achievement, feel free to ask. I have every single one except the birthright one...and it's been driving me crazy!!
Remember that "Unholy Impregnation" has an equal chance of giving a child with demon_child and demon_child_fake. The Birthright achievement only fires if you become the cult leader with demon_child or demon_child_non_pagan. (Natural born demon spawn have demon_child_non_pagan.)
I'm sure that this problem from The Old Gods DLC is probably some code that existed before M&M was released. I can't think of why they would deliberately make such a mess otherwise. I'd report this as a bug, but I'm too lazy.