Before we start, keep in mind that I am the worst writer on the site, so take any of my suggestions with a bag of salt.
Sirens blare throughout the compound, but soon, there won’t be anyone left to respond.
"Ronin! Cyberbots inbound—four of them, armed with KS-200 plasma rifles!"
Frey’s voice crackles through my radio, clipped to the waist of my cybernetic hitman suit.
I sigh. “Frey, didn’t I tell you not to play games with headphones on during my missions? And don’t yell in the damn radio.”
She huffs. “Just focus on not dying.”
The MC comes off as an ass and this is the very start of your story! Whoever this Frey is, she gave a valid info and wasn't wasting his time at all. How is she playing? What sense does it make? Maybe if she'd started with a long-winded, unnecessary joke, it would have made some point, but as it is, not so much, sorry.
A secretive, illegal research facility run by mad scientists—pushing the limits of technology beyond its time. My sister's last known trace leads me here.
Sirens blare throughout the compound, but soon, there won’t be anyone left to respond.
The cyberbots round the corner, humanoid machines clad in heavy armor.
"Intruder detected. Surrender, and you may—"
There is a fast pacing, there is a normal pacing, and then there is a teleportation between scenes. This is what you are doing. The MC just pops (and not in the term of using a teleportation power, but I am talking about narrative dissonance) from place to place like a rabbit. Like, this right here. "round the corner". Did he break into the facility? Is he in some sort of a corridor? Is he outside and the bots came from the corner of the building? You need to learn how to establish a scene.
I don’t wait for them to finish. My twin pistols bark, and the first bot collapses as a well-placed shot fries its central processing unit.
This tells me nothing, as I (as a reader) have no idea where his central processing unit is. Is it in its head? The bowels? The legs? I assume the head.
I don’t wait for them to finish. My twin pistols bark, and the first bot collapses as a well-placed shot fries its central processing unit.
Bark. As in once, I assume.
The remaining three take aim. Before they can fire, I activate the electromagnetic disruptor on my belt. A pulse surges through the air, and their systems short-circuit. I waste no time, executing them before their failsafe can kick in.
I deactivate the disruptor to keep my radio from cutting out.
“Shit, I’m out of bullets,” I mutter, tossing my guns aside. I spot a nearby combat knife and pick it up.
Do his guns hold four bullets each? Why throw the guns aside? There was no urgency!
Frey’s voice drips with amusement. “Are you really sticking with just those two pistols? You’ve been sloppy lately.”
On her end, she sits before a massive array of monitors. One screen displays a game, the others cycle through security footage of the lab’s halls.
It reads like head-hopping. I advise committing to a single POV.
The second guard trembles. “Y-you… You’re the Man of Death, right?” He raises his gun with shaking hands.
Just call him Death. Or Reaper. Or Killer. Or Murderhobo. There is beauty in simplicity.
The man nods furiously. “You’ll let me go now, right? I—I have a family, please—”
“You called me a demon,” I say, voice devoid of emotion. “And now you expect mercy?”
Considering we have no idea why these people are bad or who the MC is, he is just an unlikable asshole.
Two scientists stand frozen near a desk, their faces pale.
I lower my gun slightly. “Relax. Just tell me where my sister is, and I’ll let you live.”
They exchange glances. Then, they step toward me.
I sense something off.
Before they can act, I shoot them both.
As their bodies collapse, I spot the grenades rolling from their limp hands.
That connects to nothing in the story. Were they mind-controlled? I expected them to transform and give us badass action, but this payoff is just...worse than meh. Who acts like this?