Unfit For Greatness
A well-meaning character does more harm than good with power because he lacks the virtue to direct it.
A fundamentally good and well-meaning character who attains (either by chance or through his own effort) a position of great prestige, power, and responsibility--only to cause more harm than good because he doesn't have enough willpower, foresight, and general virtue to handle them right. Despite trying to make life better for others with his power, he ends up wasting it on petty things or unwittingly pushing them into ruin. The tragedy of this character is that he often realizes that he screwed it all up but doesn't know how to fix it. Such character may be contrasted by the one who is better suited for greatness but doesn't receive any recognition (at first). Both of them may want the same thing but by a twist of fate, the one who has the power is not the one who can pull it off. Contrast Reluctant Ruler and Cincinnatus. See also Drunk with Power and Well-Intentioned Extremist. Reality Warping Is Not a Toy is a common fantastic variation.
- Magog, the Anti-Hero Substitute of Superman in Kingdom Come, turns out to be one of more well-meaning anti-heroes. He really only wanted to Make A Better World by killing The Joker and the like and before he realized he was wrong, he was filling in Supes' shoes, which eventually culminated in the Kansas disaster.
- In Mass Effect 2, Jacob's disappeared father actually crash-landed with his crew on a planet whose environment began destroying their cognitive functions. At first, he rationed the uncontaminated food for the scientists working to get them all off the planet. Then, however, he gave in to temptation and turned the camp and mindless crewmates into his personal kingdom.
- In Labyrinths of Echo, Chief of the police General Bubuta Bokh. He earned his rank and more for exploits during the war, remains loyal, not malicious (only noisy), his abuses of power are limited to petty embezzlement and nepotism. He's also completely unfit for this job, except the part when he scares arrested folk. Note that he doesn't actually screw anything up (yet)--if only thanks to the work of much more competent lieutenants working under him.
- The one-shot JLA: Superpower is structured around this trope, in the person of Mark Antaeus.
- Irredeemable is a giant extended exploration of this trope.
- Robert Baratheon from A Song of Ice and Fire fights valiantly in a just war to dethrone a mad king, but when he takes the throne himself, he proves himself incompetent in dealing with matters of state, spends lavish amounts of money on feasts and tournaments, and his inattentiveness to his own family sows seeds of disaster.
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