Come up with an idea for a unique new comic book character whose power is plausible to have in real life but its use by the character makes him a superhero or supervillain.
The name of this new character can be "the Living Tree." The Living Tree's superpower can be his ability to use photosynthesis to regenerate his body, as well as create new appendages or other parts of his body, as well as making weapons and shields with them. The Living Tree gained his superpower working as a botanist on Mars when he was struck by a supernova blast from a nearby exploding star, which mutated his DNA and turned him into a human who could harness the power of photosynthesis in his own body.

In the continuity of the story, the Living Tree is rescued from Mars by an entity called the Apparition of Judgment, which brings the Living Tree back to Earth and plants him in the ground when it finds out the Living Tree was a human who was affected by a supernova blast and became mutated; burying the human would cause him to become one with the Earth where the Earth could revive him, and in turn, he could help to heal the Earth with his powers. The Apparition of Judgment manages to save the human and bestows the Living Tree name upon him, and commands the Living Tree to use his powers for good.

However, during the story, the Living Tree becomes a villain when he inadvertently drains Earth's resources to heal a woman he falls in love with; this causes the rest of the world's population to die off and leaves only a few humans left alive who vow to defeat the Living Tree and restore the Earth to its original health.