So. Long ago there were a group of angels who believed that the social structure of a noble family leading a kingdom was the ideal structure, and that these kingdoms should be lead by rulers blessed by heaven. Aasimars, or at least people with heavenly blessings.
These angels were known as the Kingmakers.
They helped guide mortal beings the way most angels do, through visions and divine patronage and things like that, to build grand kingdoms.
This contributed to the Age of Kings, the time period in world history dominated mostly by monarchies.
At a certain point, word got around in Heaven via prophecy that the Age of Kings was going to come to an end, and monarchies wouldn't be the dominant force anymore. Most of the Kingmakers were mad, but three in particular were so mad they decided to seize control of their chunk of Heaven and turn into fascists to prevent this from happening.
These three were known as The Subjugators because of this. They were the King, the Knight, and the Prince. The "Lady Athaliah" that Andila has been talking about was the Knight, and the Prince Enos was, well the Prince.
When they rebelled, they tried to take over a castle called Castle Digon. Over the course of the battle, Castle Digon fell from heaven, and all three Subjugators ended up trapped in their own Sisyphean torture prison for eternity.
Before they fell, however, is when Virtue comes into play.
Virtue was a being created specifically by Lady Athaliah to help raise a set of four Aasimars that she granted to mortal parents, collectively known as the Arks of Virtue. Each Ark was given a guide, an idealized version of themselves that was supposed to help teach them how to become more perfect and pass down orders from the Kingmakers. Andila's guide is Justice, so she is the Ark of Justice.
Now, all this business with the Subjugators happened a long time ago, and after their betrayal, anyone loyal to The Subjugators was captured or killed by the rest of the Kingmakers and pretty much anyone with decency. Andila escaped this.
Since then, the Justice Seekers have popped up in modern times and are after the Ark of Justice. How they know about all this, and how much they actually know, is up in the air at the moment.

Updated;
The party has since blown up 99% of the justice seekers, except for a sentient crown named Regalus.
Following this victory, andila was cut off from her powers and issued a threat from Virtue that she would be punished.
She is without her powers, and seeks a new patron.
Without her powers from Castle Digon, she can't sustain herself, and luckily has been able to get an infusion of energy from her friend Shoni, another Aasimar.