L'Arc Berg Sickle/Chronology

Volume 5
L'Arc is first introduced when Naofumi and his companions boarded the ship to sail to Cal Mira. L'Arc and Therese Alexanderite at first did not believe that Naofumi was the Shield Hero, as he didn't seem to fit any of the bad rumors circulating around the shield hero and also because they already encountered or hunted a number of fake shield heroes capable of changing shields (hired by the Church of the Three Heroes to ruin Naofumi's reputation). He advised Naofumi to stop pretending to be the shield hero, as people may dislike him. Naofumi eventually gave up in trying to convince them of him being the shield hero.

L'Arc and Naofumi agreed to level up together on the island after two days. L'Arc and Therese grew worried about Naofumi's team when they didn't return for the night and went to search for him. Naofumi was getting too comfortable with them. Before going to level up together, L'Arc told Naofumi that the four holy heroes are on the island and that he found the Shield Hero. Curious, Naofumi asked who he thought the Shield Hero was. L'Arc pointed at Mald, much to the dismay of both Naofumi and Raphtalia. Both agreed that Mald is the type to cause problems. While leveling together, both sides were impressed with each others' skills. L'Arc and Theresa began to suspect if Naofumi really was the shield hero. Naofumi then asks them to join his party.

During the fight against the wave, L'Arc concluded that Naofumi really was a Cardinal Hero and tried to kill him. Though their target was all the four holy heroes, he didn't believe the other three were true Heroes given how weak they were. However, L'Arc and Therese still couldn't beat Naofumi even with the help of Glass and so had to return to their own world.

Volume 7
In the next wave, they again traveled to the other world. When they wanted to return to their own world, they encountered Kyo, who was another wielder of a vassal weapon of their world but tried to rule the world instead of following his mission. Their Vassal Weapons begged them to stop him. Thus they stayed in this world and tried to stop him. By this time, they heard of the Spirit Tortoise defeat (its head decapitated, but not truly dead) from Naofumi and accepted the fact that he was a capable hero despite being enemies.

During Naofumi's second fight against the Spirit Tortoise (head regenerated) L'Arc met Naofumi again. He first encountered him when Naofumi tried to travel to the heart of the Spirit Tortoise and Naofumi began to attack him without listening to his explanation. But before they could finish a decisive blow, they were separated by a living wall. After that, they met him again during the battle against Kyo. L'Arc then explained to Naofumi that now he didn't have any intention to fight against Naofumi, but had to fight alongside him against Kyo.

Volume 8
Because Kyo managed to escape after the battle, they tried to chase him in the other world. After they were transported to L'Arc's world, Naofumi and Rishia were separated from the rest and so they tried to search for them.

They landed in the enemies' land and were thrown into prison. Using Raphtalia's magic they managed to escape. After being reunited with Kizuna and Naofumi, they were lectured by Kizuna, who heard what they had tried to do in the other world. After that, they once again fought against Kyo and finally beat him.