Crisanta of the Wrapped Agony is a knight devoted to His Holiness Escribar and one of the last bosses in the game.
She is seen in front of the gates that lead to Escribar, where she confronts the Penitent One in an effort to stop his journey. When she is defeated, she escapes, and in Ending A she undoes the Penitent One's sacrifice to cause the cycle of suffering to begin anew.
If the Penitent One wields the Apodictic Heart of Mea Culpa and crosses swords with her, she will fight with increased vigor, directed by the High Wills to see to his defeat. She, however, is thwarted, and the Penitent One uses the sword to free her from the influence of the High Wills. She returns to the Mea Culpa Chapel, where she gives the Penitent One the Holy Wound of Abnegation, and later on accompanies him to take down Escribar, Sentinel of the Eternal Procession and undo the High Wills in Ending C.
The official art book states that her sword is affected by the Miracle, so it is covered in red bandages that are anointed in consecrated oils just like the armor of the Anointed Legion. Further updates confirmed that Crisanta is the captain of the Legion.
In the comic, she mentions that the goals of her and the Penitent One are "different, opposite, yet complementary," suggesting that she is in direct opposition to the Penitent One's goal. This may give insight into her post-credits scene of ending A when she removes the Mea Culpa from the body of the Penitent One.