I don't know Romanian but Hungarian does have a word for dragon and a word for devil. The Hungarian word for dragon is sárkány and the Hungarian word for devil is ördög. Also Wallachia or Havasalföld in Hungarian was never part of the Kingdom of Hungary, Transylvania or Erdély in Hungarian was though until the end of World War I and many Hungarian speaking people live there to this day. Also just because someone lived in land under Hungarian rule doesn't magically make them "ethnically Hungarian".