Misguided

Misguided heroes are heroes who inadvertently do the wrong thing mostly because they don't know any better in that particular circumstance. As such for some, regardless of how good their own intentions are, they have committed their own actions for all the wrong reasons and for that, they have to learn the hard way. This mainly arises in fables where some wide-eyed youth is set to be taught a lesson over the course of the story, such as The Boy Who Cried Wolf.

This may also be done for fully grown competent characters who simply don't see a certain scope of the world they should be concerned with, such as Reeves from Final Fantasy VII or Seto Kaiba from Yu-Gi-Oh!. These characters may still take a starring role in their works, but the works themselves exist under the notion that said characters start off not knowing any better. Other times, they may be misguided/manipulated by an outside source, rather than themselves alone, and some of these cases may qualify as pawns of the villain, depending on the story or context.

They are also the heroic counterparts of delusional villains.

Misguided heroes can also make false assumptions by jumping into conclusions too quickly when believing in a false story of something or someone from what happened, but in the end, they learn that they are mistaken when they learn and see what really happened.

Misguided heroes can also be purely good if they have never wanted to cause despair or do the wrong things in the first place and have no corrupting qualities whatsoever. Even the most brilliant and commonsensical of people can be misguided by something they do or believe, sometimes taking note of that and learning for the better as time passes on.