Never Surrender (nunca te rindas): Get killed 20 times in Battlegrounds event.
I haven’t heard of anyone knowing how to unlock The Martyr. Stranger can be unlocked if one partner just doesn’t answer any of the 10 questions while Soulmate is running.
Faction Guard (guardia de liga): I’ve heard that it’s going to war 500 times. But few have it.
Pursue True Love (buscando amor): Divorce your partners 10 times. (I don’t have this, but it is known.)
The Adventurer (aventurero): Get bravery seals 150 times.
Faction Contributor: Faction Donation reaches 30,000 ambers. (I don’t have this.)
Be Another Person: Use Rename Card 10 times. (I don’t have this, and think that it requires ambers.)
Those should be roughly accurate, most of them are either common knowledge or things that I’ve got and can check.