Karski would certainly qualify as a hero of mine. He is, unfortunately reviled by substantial segments of the Polish right because of his constant campaign against all revivals of antisemitism in post-communist Poland. He is in good company there, joined by Jan Nowak Jezioranski (similar biography) Wladyslaw Bartoszewski. Or with a rather different biography, but hated for similar reasons, the great poet and Nobel Prize winner Czeslaw Milosz.