Paragon of Virtue

[Aigle édenté]

My heir has 2 virtuous traits, what should I do best to get another one and complete the achievement ?

[Inflammatus]

Change your faith to one that have your children's perks

[Aigle édenté]

hmmm I don't want to change faith

[Deusmodeus]

If his third trait is a sin, theres 1 or 2 events that can fire that will flip it when your the house head.
Or you can use the 'Repent' Oath via coronation once you become your heir.

if it's a child, set the tutor/wet nurse to increase the odds of gaining a virtue, or 'influence' the heir as your ward if you have the virtue. If you don't have the third virtue, you can gamble on his third personality trait, or give him to someone who already has the desired trait.

Originally posted by Inflammatus:

Change your faith to one that have your children's perks

Otherwise this is the answer. Convert or Reform.

If not then start building a new heir.