Wasil Kasanschiff B1917

this is my grandfather he was Bulgarian his father was mihail(michail),he was a blacksmith.my grandad was married with a least one child.his family were slaughtered inww2,I no he was Jewish,he served in the Bulgarian army an his uniform shows he was a training sergeant.he left a boy with his father after his wife was slaughtered,his son was nicoli.any help at all??