Here is his portrait.

His figure was tall and majestic, his age about thirty; he had light hair and blue eyes; his features were those of Apollo, but without his pride and assuming haughtiness; his complexion, dazzling white, was pale, but that paleness seemed to have been given for the very purpose of showing off the red coral of his lips, through which could be seen, when they opened, two rows of pearls.

He was neither thin nor stout, and the habitual sadness of his countenance enhanced its sweetness.

His gait was slow, his air timid, an indication of the great modesty of his mind.
When we entered the room Bettina was asleep, or pretended to be so.
Father Mancia took a sprinkler and threw over her a few drops of holy water; she opened her eyes, looked at the monk, and closed them immediately; a little while after she opened them again, had a better look at him, laid herself on her back, let her arms droop down gently, and with her head prettily bent on one side she fell into the sweetest of slumbers.
The exorcist, standing by the bed, took out his pocket ritual and the stole which he put round his neck, then a reliquary, which he placed on the bosom of the sleeping girl, and with the air of a saint he begged all of us to fall on our knees and to pray, so that God should let him know whether the patient was possessed or only labouring under a natural disease.

He kept us kneeling for half an hour, reading all the time in a low tone of voice.