These heroes do not always have to be the villains to be game changers, they just appear in comical titles that usually goes against the comical rules. By definition these heroes are the polar opposites of Comic Reliefs.

In other terms, Game Changer, or Knight of Cerebus is a rare type of hero who appears in media where there is usually comical or incompetent heroes and the hero quickly goes against those rules by showing themselves to be a very competent, formidable, and presented seriously enough for the story's tone to change.

For a hero to qualify in this category, the hero should provide intentions that are very serious or stern than any other hero that has appeared in a film, book, TV show, or a video game, and having the presence to perform actions that's usually not meant to be funny.

Good examples for this are Mewtwo from Pokémon, Kurumi Tokisaki from Date A Live, and Zero from Mega Man X who are seen as more competent, dark and ruthless than the rest of the heroes.

• IMPORTANT: This type of hero is not always necessary to be a one-shot hero, as it can also be applied in recurring hero in special episodes noticed in a much more serious way than how you're used to (often occurs when a character undergoes a personality change that is called "Flanderization").

NOTE: Game Changers never fall under Pure Good, because Game Changers are too prone to be Anti-Heroes and in worse cases they tend to have some villainous or morally ambiguous traits that can make them too inconsistent to count (Fallen, Lethal, On & Off, Extremist) or having attempted/committed crimes that can be considered too heinous, serious and unforgivable so that they can actually darken the mood of the story. It's also hard to forgive them for actions that they've done, even if they are otherwise not anti-heroic anymore (e.g., Zero (Mega Man)). However, there are cases where a Pure Good hero is portrayed as more serious and competent than the other heroes in their origin (e.g. Nina Fortner, John Coffey, Spider-Man (Raimiverse), Buzz Lightyear, EVE, Wiz, Samurai Jack, Mark Evans, Gwen Stacy (Spider-Verse trilogy), Ginger, Dewey Riley, Twilight Sparkle, and Queen Elsa). Pure Good heroes like the ones listed should go under the Sophisticated, Dreaded, Tragic, Voice of Reason, Strong-Willed, Redeemed Villains and/or Pragmatists categories instead.