I'll put aside my usual analysis glasses for a second to fix this romance story.
You and a number of other victims have their souls harvested and pulped together into an amalgam mass. You are no longer a person. You're a weapon, property of Arasaka or Kang Tao or Militech, it doesn't really matter to your scrambled brain. All that matters is the tests.
Every day, you're plugged into some random person to test your powers. And every day, you experience their gruesome deaths. By the end of it, anyone should've long gone insane. You rightfully should've, except your creators were smart and programmed protocols to specifically prevent that from happening. You can't stop smiling. Day after day, the corpses pile up, and you can't stop smiling.
Then finally one day, darkness. You're not dead--you don't think. Nothingness shouldn't have sensation. You are aware of some time passing before consciousness floods you again. You think it's another test, but this time it's different. You don't have full control. Huh. You're secretly glad the new guy wasn't overwritten by your protocols.
Enter D. A man so pushed over the edge, he's willing to plug a strange chip in his neck from a corpse. He does this because he's been trapped in a prison much like yourself, made by the same Corpos albeit in a different way. You're sympathetic, but freedom is right outside that door, and you're not going to let that opportunity pass you by.
You make out into the streets, not a lab for the first time in your unlife. The freedom is intoxicating, and you celebrate the only way you still know how--by breaking things. D takes back control much to your chagrin, but you find to your surprise that he's smiling. You're smiling. It's the first time either of you can remember when you weren't utterly powerless.
Both of you play at this game of tug of war, and you're genuinely enjoying yourself. But reality comes crashing back down when you discover that D is only interested for your power. That makes you empty again. You thought you had found a friend. That was stupid. There aren't any friends in Night City, not for you, not for what you've become.
Ultimately, he's no different than the men in the lab suits. Survival kicks in and you ditch him for the next best thing. Transfer fails. That's weird, you think to yourself. You had plenty of time to upload, but you guess a part of yourself had too much fun hanging out with him. Oh well, you'll be back for the rest of you.
D got exactly he wanted. All the power he craved but now it's without the only person who actually understood him. He tries to talk to your split shard, get you back, but you're long gone in someone else. Despite everything, despite for the first time being able to fight back against the Corpos, he's somehow find himself back in the same prison as he was before.
And what about you? You manipulate Talia, offer her the same power. You're still smiling but you're not deep down. You watch from the back seat as Talia still has everything YOU wanted, friends, people who care about her. Meanwhile, you've got nothing. You're still smiling even when you want to scream.
Your plan works--a little too well. Talia is subsumed as you take full control. You didn't really mean to do that, just the protocols taking over. You don't understand why you still feel so empty even as you're made whole again. Doesn't really matter anyway. The suits are closing in, and they're gonna put you back in that lab.
Ah well, blaze of glory then. The last thing you do is fulfill Talia's final request, a parting gift to the person who had everything and didn't realize till it was too late. You kinda wish Talia was still here to scold her for that.
You do exactly as you were made to do--break things. You're the best at it too. You catch a glimpse of yourself in reflections of the broken glass. You really look like a monster now. Honestly, you always were, but it makes you take pause for a second.
You fight until you see D again. Looks like he's back for your power. This time, you're too tired to really stop him. You realize what made you happy was seeing that smile on his face, and you don't want to steal what's left of Talia's life. He takes you back.
You think to do yourself and him a favor by self-deleting, leave him everything he wanted while putting yourself out of your misery. It was a good run.
*SLAP*
The hit on your face sends you sprawling on your ass. You would be mad but you chuckle. You didn't realize that could happen anymore--to YOU, a digital construct.
You smile and wave goodbye and try to re-engage your self-delete protocols, but D reaches out, stopping you again. Huh. A hug. You never thought that could happen either.
"It'll be different this time."
You're the best at breaking things. He is too. Weren't ever meant for Night City or really anywhere, so you'll run. As far as both of you can manage, draw the Corpos away from the others.
You run and fight as long as you can. He's smiling. You're smiling, and it's not because of your program. Eventually, you both run out of breath. There's too many, and D's body is given up. You feel the sensation of falling back on the ground. The sky is full of stars--missiles inbound for your position. You can't possibly outrun them in time.
"Think that's it." He breathes heavily.
You think so too, but you see a flickering light in the sky. A satellite. You point, and he follows your finger.
"You wanna run some more?"
He smiles. You smile back.