My thoughts, off the top of my head:
Three drones. Six guards. Four ways in. Only one that wouldn’t get her shot.
This needs more explanation, either via exposition or even better to be woven into the narrative. Some of this information would be better has background notes that better informs the author without ever reaching the reader directly. This is also misplaced emphasis.
The odds sucked. But failure meant Ellus wouldn’t live to see next week.
One clean run. That’s all she needed.
This is poor use of telling and will glaze most experienced readers.
Ashe crouched behind the twisted bones of a collapsed overpass, cracked goggles filtering the haze as she watched the patrol loop again. Overhead, the drones swept past—blue optics flaring through the gloom, slow and deliberate. Predictable.
This section is stronger, but will confuse the reader with apparrent contradictions. How did they sweep past slow and deliberately? It's like the author doesn't know how they want to describe the scene or what they want to primarily show. The last one word sentence is probably the character's thought.
A broken fang swung from a braided cable at her neck—jagged, dull, torn from a Lesser Stalker. The creatures scrambled passive scans just by existing. Up close, it wouldn’t fool a direct sweep, but from a distance? It made her look like static on a feed.
This is fine depending on further context.
Homemade. Ugly. Effective. Like most of the tech she cobbled together.
Short sentences are for emphasis. They work well in battle scenes when used sparingly and are cool. However, one word sentences are exceptionally sharp tools that are better off rarely utilized because they jolt the flow of the narrative. When they are utilized it should be with with extreme deliberation and care over how it affects the narrative.
This is also profoundly emphasizing telling as oppossed to emphasizing action. It's telling us what to think of the tech she cobbles together. It would be better if this line didn't exist as it offers more words for showing in another scene. Telling like this makes it easier for the author to self-contradict later, thus setting up a trip wire trap if the author tells differently later because the reader has not been allowed to see and thus form their own opinions on the MCs abilities.
The guards started moving again which meant she had ten seconds to breach the perimeter and reach cover beige she became a smear in someone’s half filled incident report.
Across the way, three security officers patrolled the perimeter—matte black armor gleaming dully beneath the haze, Comstock’s crest stamped across their chests like it meant something.
I as the reader don't know what cover beige is. It should be clearto the reader where she needs to reach. She is in hiding, perhaps the drones spotted her. Ten seconds being very specific should probably have a reason for being so, but not a fatal flaw if this is in the character's head. 'Gleaming dully' is a contradiction, probably for emphasis, but in this case its more confusing than impactful. Comstock's crest obviously means something if it is stamped across their chest, but again, this seems to be in the characters head.
Overall, from the excerpt, I'm slightly worried about how coherent the action scene will be when it starts.
