Lady Charity is the Leader of the Holy Knights and the Guardian of the Seal of Shame (if your alignment is good).
You will see her commanding Dupre to lead the holy knights into battle at Tripalo. After the battle, she is surprised to see Dupre leave, but allows him to.
If you are on the good side, you will be ordered by Vague to return with him to Capital Leo to meet Lady Charity, and find out if Regret's father is Dupre. Since she used up too much power, she promises to ask the spirits until she gets some rest, and orders Regret to protect the seals.
When you return to Leo, Charity orders you to look for Vague. After you report to her, she is saddened for the death of Vague, but tells you to protect the seal from Virulent. After Virulent is defeated, Charity will appear and reveal that Regret killed Dupre. This enraged Regret, causing him to unleash power that even harmed her, and killed Virulent. Charity still forgives him, and makes Regret the new Captain of the knights. If you are on the evil side, you will battle Lady Charity, and Virulent will take her role.