Here is the text with correct grammar, flow, and natural phrasing while strictly preserving every detail and meaning of the original narrative:
The boy, Sialy, aimed the green beam at the civil clock, and its hands moved backward.
The years accelerated, and we entered the age of machines. On the other side, the monstrous clock exploded, and the sounds of monsters rose as they began to emerge. The dragon saw the gathering of monsters and flew toward them, followed by the dinosaur, which smashed buildings. The wild cat was in the lead, and the flying eyes hovered behind the monsters. The dragon circled above the city, shouting, "Let's go to the castle! Destroy the city and its clock!" From the other side, a horde of machines advanced toward them. They scanned each monster and aimed their deadly weapons at it. The small monsters—worms and insects—advanced. They confused the machines and made them look down, while the huge monsters unleashed their fire, and flames rose. The machines shot beams everywhere and launched their small drones above the monsters. The dinosaur devoured some of them in its mouth, and they exploded in its stomach. Many fell. The flying eyes tracked those drones and drove them away.
The machines began using long-range missiles to track the movements of the flying eyes.
The boy, Sialy, and the frog were on the mountaintop, watching the battle.
They watched the fire, the missiles, and the beams destroy the monsters. The boy, Sialy, spoke to the frog, asking, "Where are the humans?" The frog replied, "My boy, they are in the age of machines. Those machines were once human."