Thanks for the comments! They really helped a lot.
A voice can be soft or silent. It can't be both, since silence is the absence of sound.
Can't the word "silent" mean both completely soundless
and quiet sound? If not, I've been wrong since I started studying English at the age of 9.

And that 20XX in the end was something that I thought to belong to the prologue, as we are talking about Megaman fic here.

Anyway, I read through the chapter one and made a few changes in sentence structures and prepositions. Also, I changed the names of the Robot Masters from the "Mega Man" form to the "Megaman" form.
*****
CHAPTER 1
Robots in ArmsAt the very moment when Private Evans’s body hit the sandy ground things started to escalate rapidly. The four trucks of the convoy broke off the formation and lined up on both sides of the jeep. Before they had even come to full stop, green robotic soldiers started to jump out of them. The robots were carrying a large shield on their left hands, while their right ones were replaced by arm cannons similar to one that had just killed Private Evans. A single robot of the same type also jumped to sight from inside of the Humvee and mounted the .50 cal machine gun on the vehicle roof.
Screeching brakes alarmed the remaining guards around the poker table. They rushed outside, switching off safeties of their assault rifles. Before they could even comprehend the gravity of the situation, the robot soldier on the Humvee .50 cal opened fire. Guards running out of the tent in a row made it look like a target practise at a shooting range. One two-second sweep of the weapon, and the whole squad was down with a cloud of dust mercifully censoring the bloody mess of their bodies shot to Swiss cheese.
Couple of robot soldiers rushed to the side of the car and fired a few well-aimed plasma shots from their arm cannons to the edges of iron-fence gate. High voltage fence wavered and sparkled as the blue bursts of plasma hit it. At the same time the alarm was raised and the Humvee’s tires screeched against the asphalt as it accelerated towards the gate. There was a series of loud bangs and another screech, as the Humvee crashed down the gate and stopped at the compound yard. Fifty cal on its roof moved from side to another to aim at the surprised people running around the yard, looking for cover.
From the crashed gate the foot soldier robots marched in, overwhelming any of the compound personnel on the yard and seizing their access to the hangars and helipads. After that was done, invading robots moved into formation for storming the compound interiors. The Humvee’s front doors opened. From the driver’s side of the car, a yellow and white coloured man stepped out. If anyone of the compound personnel would have had time to get a better look at him, they would have no doubt wondered his appearance – not only because of the orange colour of his head but also because of the scissor blades on the top of his head. He looked a little aghast of their brutal advance.
“Looks like the luck is on our side this time, Mr. Cutman.” said the crystal-helmeted man, a slight trail of smoke still following his blood-stained arm cannon. With a vicious, victorious smile on his face, he gave an arrogant look at the results of their first strike. Cutman glanced at his partner with a slight disgust for such an excitement and joy caused by this brutal bloodshed.
“It’s not over yet, Geminiman. The facility is huge and they are getting ready for us even as we speak. And who knows how much reinforcements could be on their way?” Cutman said.
“These pathetic humans are no match for the Sniper Joes, we’ll have the facility clear in a minute and we’ll be able to get the hell out of dodge long before any of their reinforcements have time to arrive.” Geminiman replied.
“Maybe,” Cutman said, “but the risks are too big, especially when considering what kind of orders we were given. ‘Get in, steal everything that isn’t nailed down and get back.’ And there’s no much doubt about who’s he going to blame if we fail.”
“True. Doctor Wily is not fit to lead such an army he possesses. Under his command, we are not going to achieve the total domination over mankind.” Geminiman said, his smile fading. His words made Cutman, who criticized Wily for different reasons, feel uncomfortable. Much to his relief, Geminiman dropped the subject as the robot soldiers – Sniper Joes – got ready for storming the facility. Geminiman nodded and one of the Joes planted an explosive charge to the blast door covering the main entrance.
Directed, bright explosion tore a hole into three-inch door with a loud, crumbling noise. Shields extended, the first Sniper Joes stepped over the pieces of blast door and through the smoke. At the very instant, loud rat-at-at-voices of four assault rifles echoed from the narrow corridors, followed by loud BANG of a detonating hand grenade. Mangled body of one of the Sniper Joes that had entered the facility was thrown back by the force of the explosion. Cutman’s face turned into a grimace of shock and hesitation, but Geminiman didn’t show any signs of setback or compassion.
“Overpower them! Advance at all costs!” he yelled, and the Sniper Joes rushed in again. Gunfire and explosions started their ear-hurting concert again, and soon they were joined by the sound of plasma cannons and screams of pain.
“We could cut our losses right here and just demand their immediate surrender, they are heavily outnumbered.” Cutman proposed with a slight prudence clouding his voice. Geminiman didn’t even turn his head from the front door to thwart this suggestion.
“No. If we start gathering them up and disarming them, it’s going to take too long. This way it’s much faster and easier…” he said, turning to Cutman with a maniacal look on his face, “…and much more enjoyable.” A long, miserable scream of pain echoed out the building and raised Geminiman’s evil smile even more.
“They have gotten through the first corridor. Come, Mr. Cutman!” he said to his reluctant partner. They followed the Joes through the hole in the blast door. Six or seven Sniper Joes had fallen in order to beat the first defenders. It’s hard to say were there six or seven, because one or two of them were blown into uncountable pieces.
Four US Army soldiers were also lying on the floor as a result of the first gunfight. Three of them were definitely dead and the fourth one was trying to crawl towards the front door with a growing puddle of blood beneath him. When seeing Cutman’s robotic boots in front of him, he lifted the pale, bloody face and looked at the robots with a silent call for help.
“There’s a medical kit in the back of the car, I could-“ Cutman started, but Geminiman didn’t bother to let him finish. He just raised his arm cannon and fired for the second time, and the bright blue laser hit the wounded soldier’s side. Man was thrown against a wall, and a long dying breath wheezed out of his mouth. Cutman looked furiously at Geminiman.
“That was unnecessary! That man was of no risk to us anymore!” he protested. Geminiman didn’t note his fury at all; he just looked towards another hallway where the sounds of battle began to rage again.
“I’m going to make sure these humans will fall. Are you coming or not?” he asked bluntly. Cutman shook his head.
“You know I can’t.” he said. Geminiman gave a mocking smile.
“Oh right… Because you’ve started to feel compassion for these pitiful life forms, or because of the cold fact of your weaknesses?” he asked. Cutman did not answer; it was not the first and not likely to be the last time when Geminiman had pointed out Cut’s “weakness”. As he was originally built by Dr. Wily’s rival, Dr. Light, as a part of an industrial robot series, deep in his programming there was a code that prevented him from intentionally harming humans. Though, Cutman thought silently, he didn’t know whether or not to call it a weakness. Right now he wouldn’t have wanted to be anything that Geminiman was.
“Go wait in the car”, Geminiman said, and activated his special power; he started to glow so brightly it was hard to look at him, and then it stopped as quickly as it had started. Now there was two Geminimen, identical from toes to malicious grin.
“Yeah, you heard the man”, said the twin, and the two ran towards the battle, laughing like two schoolboys who had just made a practical joke on the teacher. Cutman rolled his eyes, sighing as he walked out of the facility, trying not to look at the dead bodies on his way.
The engagement began three minutes ago. They had estimated that humans would have reinforcements in half an hour. Estimated. Another flaw in the plan. According to the plan, they were to escape through the teleporter at the back of one of the trucks before the human reinforcements could arrive. But what if, Cutman thought, what if the teleport truck would be destroyed before that? What if we can’t seize the compound in time? What if the reinforcements would get here sooner?
Cutman stopped his thoughts as he noticed they were the same things he had said out loud when receiving the mission from Dr. Wily. Yet his concerns had a same effect regardless did he say them out loud or just repeated them in his head. He kicked a tire of the Humvee in frustration. Wily had become even more paranoiac and deaf to anyone else’s thoughts than his own. And to his Robot Master underlings, especially to a weak industrial robot built by his rival, he was a huge pain in the-
He lost the thought pattern as the black dot in the sky he had thought to be a bird got closer. Cutman grabbed binoculars from the jeep dashboard and began to pinpoint the unidentified flying object through them.
Cutman gasped as he found it; he was looking at a man in blue outfit, flying a red robot dog with small jet engines on its hind legs. The man also had a blue helmet and he also had a plasma cannon replacing his left hand.
Megaman was coming.