Crusader Kings is a historical grand strategy / RPG video game series for PC, Mac & Linux developed & published by Paradox Interactive. Polygamy - take 3 vives and don't be chaste) or that doesn't matter - gender one (Agnatic/Enatic clans or Equality). This doctrine, along with the numerous bugs in Holy Fury, makes me question if there was any quality control or review process when making Holy Fury. Dogmatic Nature + Unrelenting Doctrine is a pretty powerful combination as it gives a flat 10% attack bonus to all units as well as makes your religion MA always high meaning easier polythesising, not to mention the removal of pagan attrition from your reformed religion, allowing you to continue ripping pagan lands to shreds without melting.
As with vanilla, the player must choose four features on reformation to define their religious mechanics and bonuses. Equality reformation doctrine unlocks far earlier but has an opportunity cost of taking the place of other impactful doctrines.