Villains Know the Hero's Weakness

"Hades: Meg, listen. You hear that sound? It's the sound of your freedom, fluttering out the window, forever. Meg: I don't care! I'm not gonna help you hurt him! Hades: I can't believe you're getting all worked up over some...guy! Meg: This one is different. He's honest, and he's sweet. Hades: (rolling his eyes) Please! Meg: He would never do anything to hurt me. Hades: He's a guy! Meg: Besides, O Oneness, you can't beat him! He has no weaknesses! He's gonna--(turns to see Hades smirking at her) Hades: I think...he does, Meg. I truly think...he does."

- Exchange between Meg and Hades where Meg has fallen in love with Hercules, refusing to work with Hades any longer––which unfortunately convinces Hades that SHE is Herc's weakness.

While the story focuses on what they are able to do to destroy the world, villains need to find out the main protagonist's weakness. Without this weakness, the story would not be nearly as interesting as it is. Exploring each superhero’s weakness can be an interesting endeavor.

Sometimes, the villains find out that the heroines (like example, Megara, Trish, Tina Carylse, etc) started to fall in love or care about the main protagonist even though they work for them which it give them a idea to bait the heroines to kill the main protagonist.

Reason why Villains want to know the Hero's weakness

 * Heroes are in love with their love interest:' When a hero fall in love with someone, it can be a problem had the villain figured it out, as it would enable him/her deal the hero/heroine easily by personally pose as his/her love interest and/or schemed to turned his/her love interest against him/her or used.
 * Losing their powers: If the hero/heroine's powers can be take away by using a machine, the villain can forced him/her to suffer despair. Some villains however, can do the same by destroy his/her home/town/planet/home reality.
 * While some hero/heroines may have friends and some family members as allies to fight the villains, its more than they had disadvantages as they may wind up as weak as the villains' minions or no match for the villains themselves that made the hero/heroine worried. In other cases, hero/heroine's family/friends may unaware with the hero/heroine's conflict with the villains and there's a chance that they trapped between that conflict and may used by villains to deter the hero/heroine.
 * Concerned if the villains find out what their civilian identity and normal lives looked like: This is the reason why hero/heroine need a secret identity as means to prevent their normal identity and those whom they cared about discovered by villains.
 * Having more than one weakness: Some heroes may have multiple weaknesses than just one which that make the villains give them a idea than before