You were once saved from a perilous fate by someone and live only because of them. It does not matter who you were before the incident, who you are now, who they were, if they just barely survived, or died in your arms, your life purpose now is to solely do what they have asked you to do. Perhaps they pushed you out of the way of a runaway cart, sacrificing themself, and in their dying breath ask you to look after their family. Maybe a messenger who sustained major injuries saving you from bandits can no longer bring an urgent message to the king and asked you to go in their stead. Either way you feel an over whelming sense of duty to upend your life for the one who sacrificed theirs.

Skill Proficiencies: It takes gall to upend your life and knowledge to find what you seek. Those in blood debts get a proficiency in Survival and History.

Languages: Those in blood debts can choose to learn the language of the one they are indebted to.

Equipment: An object either given to you by your savior or a momento of them that you religiously carry with you at all times. In fact, you might just lose your mind if you ever lost it.