Just like villains who are known as Fearmongers, Dreaded Heroes are the fear the other side has of them. These heroes has to be far away from the most feared person and also recognized as well as feared for their great skills and for their legendary achievements in their lives. Most enemies that know of their legends would not dare crossing paths with them antagonistically, for fear that they would meet the same fate of those who tried to earn their ire foolishly and those who know of them but are not their enemies would go on to speak volumes about their great skills. Overall, these heroes are those many would not mess with and to be in their path will lead to their own demise or to a fate worse than death should their wrath be triggered.
DO NOTE: Some Pure Good heroes fall under this category instead of having hatred/being misanthropes/being lethal/being assassins. Sympathy and remorse and mercy would be a good combination and conjunction of these.