Only a handful of Thunderbolt soldiers were shot by arrows when they hid behind the fort, and in terms of casualty ratio, one Thunderbolt soldier was killed or wounded by arrows, and at least five new Annexes soldiers were killed or wounded by grenades. This kind of exchange is more disadvantageous than the seemingly new annexed army, but in fact it is even more disadvantageous to the Thunderbolt army, because there are really many new annexed troops. After all, the defenders of the fortress were only one platoon, and the attacking Mongol army numbered several hundred. After a while, the fire of the fortress was suppressed a lot, on the one hand, because the new annex army was too fierce in the rain of arrows, and the soldiers guarding the fort were also killed and wounded by a third, and the rest were also suppressed and could not raise their heads. On the other hand, there are not many grenades, so they have to be used sparingly.

Under the cover of the crossbowmen, the new annexes in the river beach swarmed towards the riverbank. As soon as the new annexes, who had rushed the fastest, came ashore, they heard the sound of dense horses' hooves coming rapidly, and they let out a secret cry in their hearts, and jumped off the river bank again. At this time, the cavalry of the Thunderbolts was divided into two groups and were charging from a distance. Because there was a river bank ahead, the horses were not very fast. When they were about to rush to the river, they threw grenades against the embankment and cut into the distance in a semicircle. Each of these cavalrymen threw one grenade, and each team threw forty or fifty grenades, which was much more than the number of defenders on the fortress wall. After the dense explosion, the new annex fell in a large area in the sandy pebble field under the river bank.

Yang Wen'an saw that his subordinates were running in a mess in the river beach, and many of them retreated, and saw that the commander's junior colonel showed a cowardly mood on his face, so he immediately hardened his heart and ordered the knife and axe to behead this cronie. When everyone saw Yang Wen'an killing his cronies, their hearts suddenly sank, as if they felt that their necks were also cold, and they rushed forward one after another. Yang Wen'an's uncle Yang Dayuan was deeply respected by the imperial court before the rebellion against the Song Dynasty, and after the surrender to Mongolia, Kublai Khan also paid great attention to it. To stand out from the Jiangmen family, Yang Wenan naturally has some ability, and he took over the command at the moment. He first abandoned the two-way attack, but concentrated on attacking from the section of the river in front of the fortress, and ordered some of the archers to continue to suppress the wall, and some of them to deploy behind the spearmen, who, under the cover of the shield bearers, first rushed up the river embankment to form a phalanx.

To say that Yang Wen'an is also cunning, he did not let the spearmen go ashore first, but the shield bearers went ashore first, in addition to parrying the occasional grenades dropped on the fortress walls, he also paralyzed the cavalry of the Thunderbolt army. Sure enough, seeing that the new annexed army was swarming ashore again, the Thunderbolt cavalry, which was a mile away, rushed over again. The cavalry was coming extremely fast, and when the distance between the two sides was less than two hundred meters, the first three rows of the new annex array suddenly leaned into the trees with cold and glistening spears. Seeing this, the cavalry company commander whistled, and urgently turned his horse's head and cut diagonally to the side. The cavalry of the Thunderbolt army were all lightly armed, and they were most afraid of this kind of well-formed infantry. And at present, the new annexed army has its back to the river bank, and it is not afraid of the impact of cavalry. Even if the Thunderbolts were able to break up the thin spear formation with the help of horsepower, they would not have time to turn and rush straight down the river embankment.

Under the sudden change of formation, the Thunderbolt cavalry swept past the spear formation, but in a hurry, they did not throw many grenades, leaving their backs to the crossbowmen of the newly annexed army. After a dense rain of arrows, more than 20 horses fell to the ground. "Shoot the man first and shoot the horse first, capture the thief and capture the king first", these new annexes aimed at war horses, so the Thunderbolt cavalry only suffered a few casualties. Fortunately, the speed was not fast, so the soldiers who fell off their horses ran to the fortress after being stunned. The soldiers of the new annex army did not pursue them for fear that the cavalry would kill them back and the horse pistols, but slowly advanced in all directions to cover the landing of the new annexed army in the river flats. A few more of the fallen cavalrymen were shot as they fled, but more than ten ran to the gate at the rear of the fort and were hoisted in by the defenders with ropes.

Nearly a quarter of their horses were lost in a single charge, which made the Thunderbolt cavalry no longer dare to charge easily. Although the Thunderbolt army was able to buy war horses from the grasslands of the Tibetan region, the price was very expensive, and more importantly, the Mongols already knew the source of the thunderbolt army's war horses and strengthened their control over the grasslands of the Tibetan region, so that it became more and more difficult for the Thunderbolt army to buy war horses, and the price became higher and higher. It was not cost-effective to use these expensive cavalry to storm the infantry phalanx, so the Thunderbolt cavalry company stopped a mile away and waited for an opportunity. Yang Wen'an, who was experienced and very cautious in the use of troops, ordered the new annexed army to form a defensive formation and steadily approach the fortress. In a short time, the new annex surrounded the fortress on three sides, except in the direction of the back gate. One mile from the back door is where the Thunderbolt cavalry is formed, and the new annex army will naturally not be stupid enough to leave its back to the cavalry.

At this time, the remaining defenders of the fortress plus the cavalry that fled in, although there were still about thirty people, but the combat capability had been greatly reduced. In addition to the reason for the decline in physical strength, more importantly, the grenade has been used up almost completely. There were ten muskets in the fortress, but due to their small number and slow rate of fire, they were overwhelmed by the crossbowmen of the new annex. The defenders risked firing a single bullet from the battlements and were met with more than a dozen feathered arrows. The cavalry who fled into the fortress did not have many grenades on them, and the short muskets, although they were fast, were not accurate. On the other hand, there were a large number of archers on the side of the new annexed army, and although the rounds of covering shots rarely hit, they also made the defenders on the wall dare not take the lead at all.

When the soldiers of the new annex army in front walked to the side of the fortress wall and were about to climb the wall with ropes and long ladders, a huge explosion suddenly burst from under their feet, the power was much greater than that of grenades and muskets, and even several soldiers of the new annex army were swept to the fortress wall by the air wave, and their whole body was bleeding and they could not survive. The explosion sent the new annexes who were tiptoeing in all directions, triggering more explosions, a series of explosions that were being stepped on by the mines planted by the Thunderbolts under the wall. Immediately after that, huge explosions sounded on both sides of the fortress, and the soldiers of the new annex army who had just been surrounded on three sides fell in large pieces, and the rest cried and ran back desperately. The defenders at the head of the city shouted loudly, leaning out from behind the wall and throwing grenades and muskets, while the Thunderbolt cavalry from a mile away rushed in on horseback.

The soldiers of the new annex at this time ran as fast as rabbits, jumped off the embankment and ran across the riverbank, threw themselves into the icy water, and crawled desperately to the other side of the river with their hands and feet, as if they were no longer in danger as long as they were farther away from the fortress. It's just that they forgot about the weapon comparable to the power of mines - artillery. As soon as they fled down the middle of the beach, the five cannons on the fortress wall rang out again, and the dense projectiles the size of soybeans passed by, and they were in a large area. Although these projectiles are not as imposing as those feathered arrows with strong winds, they are much more powerful. In front of them, the leather armor on the new annex was like papier-mâché. What's more, although these new annexes are known as elites, the armor rate is only about half.

After three more rounds of shelling, the situation on the battlefield returned to the confrontation between the two sides across the river. However, only half of the 500 attacking new annex soldiers fled back, and the rest lay on the river flats and under the fortress, and a few were carried away by the current. At the moment, those lying on the ground are either out of breath or screaming. The Thunderbolt soldiers who were cleaned up of the battlefield were so screaming that they were happy. It is said that these soldiers of the new annex army were blown to the ground, and killing them at this time is a sign of mercy. At this moment, the new annex army on the other side of the river saw all this, and they were all terrified.