"My dead father gave this sword I must use this sword to avenge my family they were killed for uncertain reasons I must defend my family name oh no a member of my family was in on it I have to avenge my family I-"
Prisoner in the Imperial Prison happens to be in the cell which has an escape tunnel for the Emperor. The Emperor leaves, conveniently leaving the gate open for the prisoner. Prisoner escapes, conveniently finds a bow, sword, and several arrows. Kills rats and cultists. Watches the emperor die...
You kill your lover/innocent people. You follow an old radical to overthrow the government. You become the monarch and kill your father figure because the blind lady told you to.
-Fable 3