Reigns shouldn't be that hard to make.
The difficulty will be your lack of familiarity with C3.
There is an interesting interview with the devs here on how it was designed.
https://www.gamasutra.com/view/news/283967/Game_Design_Deep_Dive_Creating_an_adaptive_narrative_in_Reigns.php
The random events are produced with the following logic;
Imagine a bag with the interesting ability to expand and shrink in order to fit the contents you put in it. By default, that bag contains all the cards available in the game. When I’m about to select the next card shown to the player, I start by removing from the bag every card that doesn’t fit the state of the Kingdom.
I have many variations of this, but for example, if a range of cards are related to the presence of a queen but you’re not married yet, I remove those. If a card is only triggered if the church is strong but you have a weak church, I remove it too. I also remove all the cards that have been played too recently.
This creates a bag of cards that’s very different each time each time the player is about to see a new card. The final touch is to associate every remaining card in the bag with a size. The « larger » the card, the more space it will occupy in the bag.
You end up with a bag of mixed cards, large ones that take a lot of space and smaller ones. I then select one card randomly from the bag and display it to the player.
The fact that some cards are larger than others creates interesting possibilities. The probability a larger card ends up being the one that is selected is greater than the probability of a smaller one. But if the larger cards are not in the bag because they have been removed at the previous step, the overall probability of the smaller cards to be picked up increase a lot.