The following are heroes that, while still generally fighting on the good side, are willing to kill villains for any number of reasons. In order for this to be considered different from cold-blooded murder, the individual said hero kills is almost always corrupt or criminal in some fashion or they kill in self-defense.

These heroes are usually very strict in terms of not killing innocent people and can be considered in some ways like soldiers or Evil exterminators. They will not hesitate to end the life of a wicked or crazed opponent if they feel it will save the lives of themselves or innocent people.

They're the opposite of Merciful and Pacifistic heroes, and also the heroic counterpart of Homicidal villains.

Reasons of a character of being a lethal hero:

• The hero eventually killed the villain who they originally decided to spare after a fight, only for the villain attempted to backstab the hero as they turned their back on the villain that prompt the hero to do so. The way the hero killed the villain may be done out of reluctance.
• The hero reluctantly killed the villain due to lacking non-lethal solutions to defeat them or the villain in question proving to be a Pure Evil person that must be destroyed with one way or another before they can cause more widespread harm to others.

NOTE: Characters that kill in cold-blood, with no concern about "innocence" are murderers and serial killers, even if misguided. Lethal Heroes always have strict codes concerning who/why they kill and VERY few Lethal Heroes enjoy killing (e.g. Venom, Akeno Himejima), indeed they often hate the act but do so out of duty or survival. However, Pure Good heroes are never lethal, no matter how heinous the villain is. Even if they take at least one life, then that "murder" is either out of self-defense, in equitable fight, as a last resort and/or in wartime situations with regret and remorse, and/or protecting someone and/or even can be an accident. There's also been times where some Pure Goods came off as genuinely lethal or desired to kill in revenge, but eventually lost those traits. If they were to become lethal, they can no longer be. If those are the cases, they should go under Dreaded, Vengeful, Wrathful, Military, Fighters, Monster Slayers, Martial Artists, Counter-Terrorists, and/or Chaotic Good instead of this category. (e.g. General Hubert Galeforce, Athena, Geki, Mario, Kirby, Pit, Corinne D'Artagnan, Liu Kang, Captain America, Black Panther, Spider-Man (Marvel Cinematic Universe), Samurai Jack, She-Ra/Adora, Madoka Kaname, Preston Garvey, Leonardo (TMNT 2003), Fox McCloud, Mipha, Yoda, Link, Marth, Fa Mulan, Jonathan Joestar, Captain Rex, Omega, Ronald "Red" Daniels, Jack Cooper, Qui-Gon Jinn, Aragorn, Nepgear, Po, Anne Boonchuy, and Gizmo).

• However, lethal heroes can still be sympathetic if their lethalness is limited and usually kind and benevolent toward everyone else (e.g. Sidney Prescott, SpongeBob SquarePants, Patrick Star, Mr. Wolf, Claude von Riegan, Urbosa, Wyldstyle, Korra, Sailor Moon, Ajay Ghale, Invincible, Banjo, Clementine, Rey, Rango and Alan Grant).

Heroes do not necessarily have to kill someone to qualify, some of them just have the potential to do so and can be seen violently attacking someone else (e.g. Hiroki Sugimura and Mr. Wolf).