Genshin Impact.

Lin Feng looked at the dark power gushing out of the mysterious crack in the sky, and a sense of mission arose in his heart. The Knights of Favonius also quickly entered combat mode, ready to deal with this sudden crisis.

Amber pulled the bowstring tight, and a rocket condensed instantly: "This force looks malicious, everyone be careful!" Lisa's hand flashed with lightning, charging her magic. Feng Feng also mobilized the element fusion technique he had just mastered in the trial, and was ready.

The dark forces surged like a tide, withering the grass and cracking the earth wherever they went. A group of distorted shadow monsters emerged from the darkness and pounced on Mondstadt with their fangs and claws bared.

"For Mondstadt!" The Knights shouted and rushed towards the monster. Lin Feng followed closely behind, the elemental power in his hand bursting out. He merged the water and ice elements to create an ice spike area, freezing the monsters in front. Amber's rocket streaked across like a meteor, hitting the frozen monsters and causing a series of explosions.

Lisa's lightning magic was even more powerful. She waved her staff and several lightning bolts fell from the sky, electrifying the monsters and turning them black. With everyone's coordinated efforts, the first batch of shadow monsters were successfully repelled, but the dark power continued to pour out.

As the battle continued, Lin Feng gradually felt powerless. His elemental power was consumed too much, and his movements began to slow down. A shadow monster took advantage of the opportunity and pounced on Lin Feng. At the critical moment, a flash of sword light passed by, and the monster was cut in half. It turned out that Kaia, the cavalry captain of the Knights of Favonius, arrived in time.

"Hold on, my friend!" Kaia encouraged, joining the battle. With Kaia's support, the pressure on everyone was reduced. But the dark power in the crack suddenly intensified, and a huge shadow lord slowly stepped out of the crack. It was dozens of meters tall, shrouded in darkness, and wielded a huge shadow sickle in its hand.

The Shadow Lord roared, and the sound waves shook everyone's blood. It swung its sickle, and a dark energy wave attacked the crowd. Feng Feng and the others used their strongest elemental skills to resist. But the energy wave was so powerful that everyone was pushed back dozens of meters.

"This is not a solution. We must find the source of this dark force and close the crack!" Lin Feng shouted.

Kaeya nodded in agreement: "I will hold this lord back, and you guys find a way to get closer to the crack!" After that, Kaeya's body of ice elements burst out, and he turned into an ice shadow and rushed towards the Shadow Lord.

Lin Feng, Amber and Lisa took the opportunity to bypass the battle area and rushed towards the crack. On the way, shadow monsters kept coming to block them, but the three of them cooperated tacitly and defeated the monsters one by one.

Finally, they came to the bottom of the crack. Lin Feng found that the crack was surrounded by complex rune formations, which kept the crack open and continuously released dark power.

"This should be some kind of dark magic circle. We must destroy its center to close the crack." Lisa said as she observed the formation.

The three of them began to look for the center of the formation. After a careful search, Amber found a black crystal emitting a strange light, which must be the center of the formation.

Just as they were about to destroy the center of the formation, a black shadow rushed out from the side and injured Amber. It turned out to be a capable subordinate of the Shadow Lord, the Shadow Assassin. Its figure was erratic and extremely fast, and the dagger in its hand flashed with cold light.

Lin Feng and Lisa immediately protected Amber behind them and fought a desperate battle with the shadow assassin. Feng Feng fused the fire element with the lightning element to form a series of flames and lightning, which blasted towards the assassin. Lisa cast a powerful binding magic to try to restrict the assassin's movements.

Under the joint attack of the two, the Shadow Assassin gradually fell into a disadvantage. But it suddenly released a dark smoke, took the opportunity to escape and rushed towards the center of the formation.

"Oh no! It's going to destroy the center of the formation, making the crack unable to close forever!" Lin Feng was anxious and chased after it with all his might.

At the moment when the shadow assassin was about to touch the center of the formation, Feng Feng leaped up, gathered all the elemental power in his body into his palm, and faced the shadow assassin with a palm strike. The powerful impact knocked both of them away.

Lisa saw the right moment and struck the shadow assassin with a bolt of lightning, completely destroying him. Lin Feng ignored the pain, got up, and destroyed the center of the formation with a powerful blow.

As the center of the formation was broken, the cracks began to slowly close, and the dark power gradually dissipated. The Shadow Lord lost his source of power, and under Kaeya's continuous attack, he finally fell down.

After the battle, the residents of Mondstadt came out of their homes and cheered for the victory. Although Lin Feng and others were exhausted, they were relieved to see that the city was safe and sound.

However, they all know that this is just the beginning. The emergence of the dark power is no accident, and there must be a bigger conspiracy behind it. After a short rest, Lin Feng decided to embark on a journey to find the truth and protect the peace and tranquility of the continent of Teyvat.