Chapter 521: The aftermath of the Fantasy Island adventure and the journey to fight against the mons

Luffy and the others began to focus on attacking the black-robed man's magic wand. Luffy used his rubber arm to launch himself to the black-robed man's side, and then punched the wand with all his strength: "Rubber? Great Ape King Spear? Breaking the wand!" The punch hit the wand hard, and the wand broke instantly. The black-robed man screamed in pain, and their magic power also weakened.

Zoro, Sanji and others took the opportunity to launch a more fierce attack. With the concerted efforts of everyone, the black-robed man was finally defeated. They successfully strengthened the seal of the crystal ball and prevented the leakage of powerful power.

After leaving the crystal tower, they continued to explore the island. On the other side of the island, they found a huge maze. The walls of the maze were made of huge stones, which were engraved with various strange patterns and symbols.

"This maze looks interesting, let's go in and take a look!" Luffy said excitedly. They walked into the maze and soon found that it was full of various traps and puzzles.

Some traps are spikes hidden in the ground, some are hidden arrows shot from the wall, and some are illusions that will make people lose their way. Luffy relies on the flexibility of his rubber body to avoid traps many times, and Zoro, Sanji and others also rely on their keen perception and strong strength to deal with various dangers.

Usopp played an important role in solving the puzzles. With his rich imagination and knowledge of traps, he led everyone to solve the puzzles step by step. For example, there was a puzzle that required pushing stones in a specific order. Usopp found the correct order by observing the patterns on the wall, successfully pushed the stones, and opened the way forward.

After a difficult exploration, they finally walked out of the maze. At the exit of the maze, they saw an ancient castle. The gate of the castle was closed, and there was a mysterious atmosphere around it.

Luffy went forward and pushed the door hard. The door slowly opened and a melodious music came from inside. They walked into the castle and saw a group of people dancing in the hall. Their faces looked a little blurry and their movements were mechanical and stiff.

"These people don't look right." Robin said softly. Suddenly, the dancers stopped, their eyes flashed red, and then they rushed towards Luffy and others.

Luffy used his rubber arms to throw away the people who approached him one by one: "Rubber? Whip!" Zoro, Sanji and others also took action and fought with these strange people. During the battle, they found that these people seemed to be controlled by some kind of power.

Nami summoned lightning with the weather stick and struck these people in an attempt to wake them up. Usopp took out a special "mind recovery bomb" and fired it at the crowd. After the bomb exploded, it emitted a special energy that gradually restored some people's eyesight.

Chopper transforms into a fighting form, using his antlers and fists to attack those who are still controlled. Robin uses the power of the Hana-Hana no Mi to search for the source of control in the castle. Franky attacks the enemy with laser beams, while Brook uses the sound of the soul to soothe the souls of those who are controlled.

After some efforts, they found the source of control over these people, which was an evil heart deep in the castle. This heart exudes black light and constantly releases the power to control others.

Luffy and the others rushed towards the evil heart. Some defense mechanisms appeared around the evil heart, and various dark energy tentacles stretched out towards them. Luffy used his rubber arms to fight the tentacles: "Rubber? Snake Cannon!" Zoro, Sanji and the others also used their strongest skills to fight the tentacles.

In the fierce battle, they found that the weakness of the evil heart was a red core in its center. As long as this core was destroyed, the evil heart could be destroyed.

Luffy seized the opportunity and used his rubber arm to catapult himself to the center of the evil heart, then punched the core with all his strength: "Rubber? Great Ape King Spear? Heart Destroyer!" This punch hit the core with great force.

The evil heart let out a sharp scream, then broke into countless pieces and dissipated in the air. Those who were controlled also returned to normal, and they were grateful to Luffy and others.

After resting in the castle for a while, Luffy and his companions continued to sail on the sea. They didn't know what kind of challenges they would encounter in the next adventure, but they were not afraid, because they were the Straw Hat Pirates, a group of adventurers who always pursued their dreams and moved forward courageously. They believed that as long as everyone was united, nothing could stop them from continuing to write their own legendary stories on the Grand Line.

After a while, they came to a mysterious sea area. There were always strange stars twinkling in the sky of this sea area, and these stars seemed to be pointing in a certain direction.

"These stars look strange, could they be giving us a hint?" Nami said, looking at the stars in the sky. Luffy looked in the direction indicated by the stars and saw a faint island in the distance.

"Anyway, let's go and see!" Luffy decided to head towards the island. When they approached the island, they found that the sea water around the island was a deep blue, as if it contained endless secrets.

When they landed on the island, they found that the plants on the island were very large, the trees were towering into the sky, and the grass was taller than a person. In the center of the island, there was an ancient observatory. The observatory had a unique architectural style and was surrounded by various astronomical instruments.

Luffy and others walked into the observatory, which had a huge astronomical telescope. Usopp curiously went up to watch, and suddenly, he saw an amazing sight.

"Everyone, come and see, I saw a huge black shadow, like some kind of huge creature, it is moving towards our island!" Usopp shouted in horror. Luffy and others looked through the telescope and saw a huge black shadow moving through the sea.

"Whatever it is, we must be ready to face the challenge!" Luffy said with a clenched fist. They began to set up defenses around the observatory, waiting for the unknown creature to arrive.

Soon after, a huge sea monster emerged from the sea. The body of this sea monster was like a small mountain, covered with hard scales, and its eyes were like huge lanterns, emitting a fierce light.

"Wow, what a big guy! But we won't back down!" Luffy shouted excitedly. He stretched out his rubber arms and rushed towards the sea monster: "Rubber? Bazooka!" His attack hit the sea monster's head hard, but the sea monster just shook its head and was not seriously hurt.

Zoro, Sanji and the others also displayed their special skills. Zoro's sword flashed across the scales of the sea beast, splashing a string of sparks: "Three Swords Style? Tiger Hunt!" Sanji's fire kick slightly charred the surface of the sea beast's body: "Devil Wind Kick? Mutton SHOT!"

Nami summoned lightning with the weather stick and struck the sea beast. Usopp took out a special "sea beast penetrating bomb" and fired it at the sea beast. The bomb exploded on the sea beast's body, creating some small holes. Chopper transformed into a giant form and hit the sea beast with his body. Robin used the power of the Hana-Hana Fruit to set up obstacles around the sea beast to restrict its movements. Franky attacked the sea beast's eyes with laser beams, and Brook used the sound of the soul to interfere with the sea beast's nerves.