Just random scenes I've thought of. Or y'all. Open input or whatever.

A scene where a sociopath is going to kill a person, they beg "what did I do?! I'm sorry" and all that like they do.
The murderer stops. Blinks.
"You didn't do anything. I'm not mad at you. I don't want revenge."
Person: "so you aren't going to kill me?"
Murderer: "Of course I am."
Person: "but why?"
Murderer: "I'm a crazed murderer. Crazy. Not sane. Duh" *murders person*

The 2nd main character looks at the lifeless form of the main character beside them on the floor.
"What did you do?" they demand to the antagonist.
"They're dead. And you'll join them."
They run headfirst at eachother. The antagonist hits first, and drives them both to their knees. But the 2nd main character has also struck a fatal blow, and they both die together, forever forgotten.

I feel like the story would center the Killer. As he deals with the problems of dealing with people and suppressing the urge to kill.

Dealing with people day to day, and as he kills them.

Danny was a good kid. A little shy but not in his eyes. He thought he was as social as he needed to be. Danny's parents were always telling him to be careful. "The world has changed since we were your age", they'd drone on and on. All those things happened in other places. Nothing ever happened here. That's when he noticed the black sedan parked across the street.

The boy looked down the sight at the man he had hunted across the world. The man he had built his life around in the pursuit for revenge. His finger tightened on the trigger. "I'm going to kill you!" he spat, his jaw was clenched, his face contorted in hate. The man who had taken everything from him casually shifted, hands in pockets and observing him curiously. "Pardon my rudeness, but who are you?" the boy nearly pulled the trigger at the question, but paused, wanting the murderer to fear, to plead. Nothing was happening how he had imagined. "You know who I am! You killed my family!" the boy almost screamed the words. "Hmmmm..." the man seemed to muse almost lathargically. "I'm afraid you will have to be more specific. I've killed a lot of people in this business." As if the man hadn't been running. As if he didn't know. The man seemed to catch the disbelief in the boy's hateful gaze. "What, you think I remember your family? You think I care about a few lives amongst all the rest?"

Hah my muse goes long winded when I get started.