A Perfect Circle

The real condition is kinder than the description: you need no more than 12 unique characters among your ancestors out to great-great-great-grandparents (the game counts 50+ "missing unique ancestors" out of a possible 62). Watch out: a lowborn parent counts as a whole tree of unrelated ancestors, so every slot must come from your one proudly compact gene pool. The wiki setup: a designer ruler in Iceland, Messalianism faith (permits the necessary marriages, gender-equal), Pure-blooded, restricted diplomatic range, then three generations of full-sibling pairings; play a female ruler or set the sexuality game rules to minimise cuckoldry, which is the biggest threat. BIG CAVEAT: as of April 2025 the wiki reports this bugged and never triggering on the current patch - the working route was rolling back to 1.13.2 via Steam Betas. Check before you commit three generations to it.