Lore Subject: The Physician
The Physician. A trusted and man by the people, he willing to help anyone, from royalty to the poorest citizens. Having experienced the treacherous lands past Castle Adiart, he is familiar with diseases and poisons of all kinds., and more familiar with death than any man would wish. He even gained resistance to the poisons that lie outside the castle walls. As darkness and corruption began settling over Castle Adiart, he realizes he must destroy the source of evil if he wished to save the people. So, every morning, he quickly identified and left notes of how each person was killed. Hopefully, we wouldn’t share their fates…
I personally imagine the Physician as a man of the people. Since his ability Remedy Studies makes him immune to poison, Heal both saves someone AND cures poison, and that he can easily identify how someone died, I think that him previously living outside the castle gates gives an answer towards this.