it was not Lucas' biological parents, the white haired guy is his master... The very first magician of the black tower.... His master fell in love with a normal human girl and have a family, unfortunately cause they were both (the wife and child) normal, they also died in old age leaving Lucas' master alone... So that is why his master is wishing that Lucas will not experience/understand the pain of losing someone.. then Lucas compared his master to Athy... He did not want Athy to drown in despair if ever Claude dies and choose to die as well...