Chapter 520: Exploring the Secrets of the Crystal Tower and the Battle to Protect It on Fantasy Isla

Luffy and his companions fought hard, but the magic power of the Demon Captain was so strong that they gradually fell into trouble. At the critical moment, Luffy discovered that the source of the Demon Captain's magic power was a magic gem in his chest. As long as this gem was destroyed, the power of the Demon Captain could be weakened.

Luffy and the others began to focus on attacking the gem on the Demon Captain's chest. Luffy used his rubber arm to launch himself to the side of the Demon Captain, and then punched the gem with all his strength: "Rubber? Great Ape King Spear? Demon Breaker!" This punch hit the gem hard, and the gem shattered instantly. The Demon Captain roared in pain, and his magic power weakened.

Zoro, Sanji and others took the opportunity to launch a more violent attack. With the concerted efforts of everyone, the demon leader was finally defeated. He returned to his original appearance, fell to the ground, and lost the ability to resist.

With the defeat of the devil leader, the residents of the island gradually regained their consciousness. They were grateful to Luffy and his friends and held a grand celebration for them. Luffy and his friends spent a happy time on the island and then continued sailing on the sea.

After Luffy and his companions bid farewell to the Island of Joy, they continued to sail on the Grand Line. A few days later, they saw an island in the distance that was shining with a strange light. The light seemed to be constantly changing colors and shapes, as if it had its own life.

"Wow, that island looks super cool! There must be great adventures waiting for us!" Luffy shouted excitedly, his eyes shining brightly. The Thousand Sunny accelerated and headed towards the island.

When they approached the island, they found that the surrounding sea was filled with various whirlpools. These whirlpools emitted strong suction force, and if they were not careful, they could be sucked into the seabed.

"Everyone be careful, these whirlpools are dangerous!" Franky shouted, while maneuvering the boat with all his strength to try to avoid the whirlpools. Luffy stretched out his rubber arms and pulled his companions who were close to the whirlpools back to the boat one by one.

After a difficult voyage, they finally managed to approach the island and land. As soon as they stepped onto the island, a strong energy wave hit them, making their bodies slightly numb.

"The energy on this island is very strong, everyone should stay alert." Robin frowned and said. They walked along a path paved with colorful stones and saw some strange creatures on the road. These creatures seemed to be made of crystals, with light flashing inside. They jumped and shuttled between the stones, as if conveying some kind of information.

As they walked, they came to a huge square. In the center of the square stood a crystal tower that reached the sky. The tower was surrounded by various mysterious runes and patterns. These runes kept flashing, as if telling an ancient story.

"This tower looks like the key, let's go in and take a look!" Luffy rushed to the Crystal Tower without hesitation. However, when he approached the tower door, an energy barrier suddenly appeared and bounced him back.

"Damn, what is this?" Luffy said as he rubbed his body. Robin carefully observed the energy barrier and said, "This may be an ancient defense mechanism that requires specific conditions to open."

Just as everyone was thinking about how to break through the barrier, the crystal creatures in the square suddenly gathered together, their bodies began to merge, and gradually formed a huge crystal giant.

"Outsiders, you have trespassed into the holy land and must be punished!" The Crystal Giant made a deep and loud voice. Luffy jumped up and responded, "We just want to explore this island, we have no ill intentions!" But the Crystal Giant obviously ignored it, it raised its huge arm and smashed down towards Luffy and others.

Luffy quickly stretched out his rubber arms, wrapped them around the giant's arms, and pulled hard, trying to pull the giant down: "Rubber? Tug of war!" Zoro, Sanji and others also displayed their special skills. Zoro's sword flashed across the giant's body: "Three sword styles? One big? Three thousand? The world!" Sanji's flaming kick caused cracks to appear on some parts of the giant's body: "Devil's Wind Kick? Devil's Dance!"

Nami summoned lightning with the weather stick and struck the giant: "Thunder Dragon!" Usopp took out a special "crystal destroyer bomb" and fired it at the giant. The bomb exploded on the giant, splashing a piece of crystal fragments. Chopper transformed into a giant form and hit the giant with his body. Robin used the power of the Hana-Hana Fruit to find the weakness of the giant, Franky used laser beams to attack the vital parts of the giant, and Brook used the sound of the soul to interfere with the giant's actions.

In the fierce battle, they found that the core of the giant was a huge crystal on its forehead. As long as the crystal was destroyed, the giant could be defeated.

Luffy and the others began to focus on attacking the crystal on the giant's forehead. Luffy used his rubber arm to launch himself onto the giant's forehead, and then punched the crystal with all his strength: "Rubber? Great Ape King Spear? Crystal Breaker!" This punch hit the crystal hard with great force.

The crystal shattered instantly, the giant let out a huge scream, and then turned into countless crystal fragments and dissipated in the air. As the giant disappeared, the energy barrier of the crystal tower also disappeared.

They walked into the crystal tower, which was a huge space with various crystal containers placed around. The containers were filled with liquids of different colors that emitted charming light.

Deep inside the tower, they saw a huge crystal ball. It seemed that a powerful force was sealed in the crystal ball, and this force was constantly surging in the ball, trying to break the seal.

"This power is so strong that it could cause a huge disaster if released." Robin said solemnly. Just as they were studying how to strengthen the seal, a group of mysterious black-robed men suddenly appeared in the tower.

"You stupid guys, you actually destroyed our guardian giant and tried to interfere with the power of the crystal. Today is your doom!" The leader of the black robes said angrily. Luffy responded fearlessly: "We will not let this power be abused, and you can't stop us!"

The black-robed men cast magic spells one after another, and various dark energy balls flew towards Luffy and the others. Luffy used his rubber arms to swat away the energy balls one by one: "Rubber? Machine gun!" Zoro, Sanji and the others also quickly launched a counterattack.

Zoro's sword flashed in the dark energy: "Three Swords Style? Demon Slash!" Sanji's fire kick collided with the dark energy, emitting a dazzling light: "Devil Wind Kick? The finishing touch!" Nami used the weather stick to summon a strong wind to blow away the dark energy. Usopp took out the newly invented "magic cancellation bomb" and fired it at the black-robed man. The bomb exploded and canceled out part of the magic attack.

Chopper transforms into a special form and uses his body's strength to resist the dark energy. Robin uses the power of the Hana-Hana Fruit to set up obstacles around the black-robed men to restrict their movements. Franky attacks the black-robed men with laser beams, while Brook uses the sound of the soul to interfere with the black-robed men's magic.

During the battle, they discovered that the source of the black robes' magical power was the black robe wands in their hands. As long as these wands were destroyed, the power of the black robes could be weakened.