Apparently, Disillusioned Adventurers Will Save the World Novel Volume 1 is written by Shinta Fuji.

Nick used to be a member of a veteran adventurer party, helping his undisciplined friends with the accounts whenever he could. But what was his reward? Getting accused of embezzlement and kicked out by the leader he respected. Before long, he finds a few other jaded adventurers and kindred spirits, and together, they form their own unstoppable party!

Apparently, Disillusioned Adventurers Will Save the World Novel Volume 2 is written by Shinta Fuji.

Betrayed and kicked out of his adventurer party, Nick thought he might never trust another again. However, it isn't long before he finds new comrades with similar experiences: Tiana, a mage and former noble lady, Zem, an excommunicated priest, and Karan, a female dragonian warrior. Together, they form an adventurer party called “Survivors” and are later joined by the Sword of Bonds. But just as things start picking up for them, Nick runs into his ex, Claudine, and they get dragged into a duel with her adventurer party. Can the newly formed Survivors win against a group active in the underworld?

Apparently, Disillusioned Adventurers Will Save the World Novel Volume 3 was written by Shinta Fuji.

The Survivors were formed when four adventurers decided to band together after being betrayed, but thanks to the Sword of Bonds, the tentative trust they’ve built has made them more powerful than ever. After Nick and Tiana took down the Iron Tiger Troop and the Sword of Ruin as the Lovely Paladin, the Survivors have returned to funding their vices—until they hear of a mysterious monster lurking in the city!