Supposedly a powerful Cleric - may be able to raise dead. Looks after the insane? Has been perpetually youthful since he arrived in Barovia around 100 years ago.
Dimitri Krezov said that he is very well spoken but not very talkative; wine is taken up to the Abbey of Saint Markovia occasionally as an offering.
Is in fact a Celestial being and hopes to cure Strahd von Zarovich (and by doing so "cure" Barovia) by presenting him with the constructed Vasylka as a bride.
It seems he may actually be insane himself.