The type of irony described, where the villain is revealed to be the true hero of the story, falls under:
C. Situational Irony - the opposite of what is expected happens
Explanation:
1. Situational Irony occurs when the outcome of a situation is different from what was expected.
2. In this case, the readers and characters initially perceive the villain as the bad guy, which is the expected norm in most stories.
3. However, the twist reveals that the villain is actually the hero, contrary to the initial assumption, creating a situation where the outcome is unexpected and contrary to what was believed.
This scenario fits the definition of Situational Irony because it involves a significant contrast between what is anticipated (the villain being bad) and what actually occurs (the villain turning out to be the hero).