The term 'heartless one' can be described by two crossword solutions: Tinman (6 letters) and OGRE (4 letters). The Tinman is a character from the classic novel The Wonderful Wizard of Oz by L. Frank Baum. He is a man made of tin who has no heart and must search for one. An OGRE is a mythical creature often depicted as a large, cruel, monstrous humanoid. Ogres are usually portrayed as heartless creatures that terrorize humans.