Apparently, Disillusioned Adventurers Will Save the World Novel Volume 4 was written by Shinta Fuji.

After a fierce battle, Nick and the others succeeded in crushing the demon worshipper White Mask. The guild is extremely happy with their performance, and so the Survivors are entrusted with a job to guard a live concert by an idol. But when they discover counterfeit tickets-and a connection to the demon worshippers-they doubt that this is a normal escort job. Then Sun Knight captain Alice shares her suspicions about Nick's former party member Garos, shaking him to the core. Karan is there to support him, but her feelings for him seem to be changing…

Apparently, Disillusioned Adventurers Will Save the World Novel Volume 5 was written by Shinta Fuji.

The Survivors failed in their mission to guard the idol concert. Diamond is gone, and Karan has fallen victim to an incurable curse. And unfortunately, with Garos dead, they have no clue how to help Karan. When Argus, leader of Combat Masters and Nick's mentor appears, even the Union spell is no match for Labyrinth City's most powerful. However, with the help of a certain someone, it seems they might just be able to turn the tables…until Callios puts the Survivors in an even more desperate situation. Is this the end for the disillusioned adventurers?

Apparently, Disillusioned Adventurers Will Save the World Novel Volume 6 was written by Shinta Fuji.

Nick/Zem face off against Nick's one-time mentor, Argus, and the Sword of Tasuki deep in the labyrinth. Tiana confronts Bellocchio, her former teacher, barricaded inside Starmine Hall. Karan searches for the Magic Mirror of Marde—the key to turning the tide of battle—filled with a newfound power. As the enemy breaks through Tiana's siege, the Survivors are brought together once more…but will they be able to stop the Sword of Tasuki from completing his true plan of resurrecting the demon god?!