Let me warn you again in case you didn't take the description seriously-this is dark. Really really dark.
"In case you needed to kill me? You can't. I've tried. I got low, put a bullet in my mouth. The Other Guy spit it out."
Life is pain.
He doesn't want to do this anymore. He's tired of waking up naked who-knows-where, sometimes injured, with only a vague but for that all the more terrifying idea of what happened in the preceding hours.
This time he's at the foot of a steep rocky slope, something between a hill and a cliff, that he vaguely recognizes as being near the village where he currently lives. Lived. Doesn't live there anymore, he knows that much. If there even is a village anymore. This time he has some idea how he ended up there, why the world is foggy with pain. A hazy recollection of waking sometime earlier and farther up, disoriented, and slipping. It's a long rocky fall, but it seems the world is too cruel to properly put him out of his misery.
This time, he's not going to pick himself up. He's not going to slink away somewhere else, carve out a niche and delude himself into thinking that this time things won't go wrong. This time they won't go wrong, because there won't be a this time. He's done.
He lies there, staring at the sky. It feels as though half the bones in his body are shattered, and blood still flows slowly from a myriad of cuts. He wishes it would flow faster. Then again, it's fitting that a monster should die like this, slowly and painfully and alone. He deserves no less. And yet he wishes he weren't so alone. He closes his eyes and tries to picture her face one last time. Only to jump out of his skin, broken body or no.
They never go away. The destruction, the rubble, the bodies. Branded on the insides of his eyelids. He doesn't know anymore which images he saw through his own eyes and which…not. It doesn't matter. They haunt him the same. He doesn't know the last time he truly slept. Every time he closes his eyes, he sees them. Fitting, he supposes, that the last thing he sees will be the destruction he wrought on the world.
But it isn't. Some of the men from the village find him and insist on binding his wounds. Then they leave him to his own devices in what remains of his house, because he is a doctor and he can take better care of himself than they can. He is glad when they leave. He wants nothing more than to go to sleep and never wake up. That won't happen though. As soon as their wives and mothers hear that the sweet young doctor was injured by the monster that flattened their village, they will descend on him. And all he wants is to die in peace.
He has a gun in his dresser. For self defense, he'd told himself, though he doesn't exactly have need of a weapon to defend himself. He can end this nightmare. He can ensure that the monster never hurts anyone else. He puts the barrel in his mouth. Will anyone even miss him? The villagers hardly know him, a stranger recently arrived and willing to tend their sick in exchange for food. She doesn't know where he is, for both of their safety, will never know what became of him. It's best that way.
He pulls the trigger.
The other guy spits it out.