Light Novel Volume 12/Synopsis

Prologue: The Shield Hero's Morning
Naofumi started training to use Hengen Muso. His training was routine was different from others due to the Legendary Shield's interference. Due to the usage of Greed and Gluttony skills, Ren now suffers various handicaps and level drop. After looting from the dead body of the otherworldly invader from their previous fight, S'yne uses its translation accessory to make her doll familiar speak for her without interference.

Chapter 1: Instant Awakening
As his unique way to train in Hengen Muso style, Naofumi spar with Atla due to her aptitude for the art. When Naofumi is exhausted, Raphtalia takes a turn to spar. Naofumi observes the fight as a way to sense life force. After the sparring session and had lunch, they went to visit the weapon shop guy at Castle Town.

Chapter 2: The Alchemist
Naofumi orders a katana using materials that previously used to make a prototype shield. Tolly and the weapon shop guy remembered that their master is a swordsmith specialized in making katanas. Naofumi went back to the village after parting with them. Some of the residents inform Naofumi that some alchemist from Faubrey was looking for him. Seconds later, the said alchemist appears and inspects Filo. The alchemist introduces herself as Rat and stopped her inspection at Naofumi's request. They then have a long discussion about monsters. After finding out about Rat's thoughts and philosophies, Naofumi decided to accept her in the village, on condition that she becomes his slave as insurance of her honesty.

Chapter 3: Filolials and Dragons
Naofumi found a mountain of gifts outside the village. Based on the characters and type of ink used on the gift's crates, Eclair suggests that it was from Siltvelt or Shieldfreeden. Among other gifts, Rat tells Naofumi that a dragon egg is among them. A monster enthusiast slave introduces herself as Wyndia because Naofumi would give her a weird nickname unless he knew her name. Naofumi, Rat, and the others then talk about dragons. Oddly, Wyndia seems to know much about it and shows a hint of hostility toward Ren who has killed a dragon. Naofumi decided to hatch the egg and set the gender as male. Sometime later, after figuring out the curse effects one by one, Ren figured out that he can't gain experience until the effects wear off. In just a few days, Rat has developed the bioplants for various uses. The dragon egg is hatched, and Wyndia on behalf of the villagers named him Gaelion.

Chapter 4: Stardust Blade
Naofumi went to the Melromarc weapon shop again to check the work on the katana he ordered. The work is finished in the form of Siderite Katana, granting Raphtalia the Stardust Blade skill. A week has passed, recently someone in the village has been playing pranks on Naofumi and annoys him.

Chapter 5: Knock and Run
The culprit turned out to be Gaelion, who wants Naofumi to play with him. Naofumi punished him for his pranks but also decided to play with him from time to time. At night, Naofumi, Raphtalia, and Sadeena discuss another annoying thing that bothered Naofumi: Atla. In the midst of the conversation, Gaelion is rummaging through Naofumi's bag of materials.

Chapter 6: Level Drain
Gaelion gulped a dragon emperor core fragment. He then went out of control and flew off somewhere. Sadeena tells Naofumi about dragon core and how a soul of the dragon in it might have taken over Gaelion. In separate places, Filo seems to caught a curse that now gradually saps her level down due to a dragon core she gulped long ago and transferred it to Gaelion. Atla also notices that a similar thing happened to Naofumi due to his shield has absorbed a fragment of dragon core as well. After hours of travel, Naofumi and the party arrived at the village where they fought the Zombie Dragon.

Chapter 7: Plagued Earth
Along the way to Gaelion's spot, Wyndia shows an aptitude to a magic that borrows power from her surroundings. Sadeena demonstrates an advanced use of similar magic to teach Wyndia how to strengthen it. As they get closer, the sleeping Gaelion woke up and retreat to a cave. They enter the cave and once again approaches Gaelion, who now oozing out black sludge all over his body. Filo along with Atla and Raph-chan shows up as Naofumi enters the cave. Atla reported that Filo suddenly went out of control and follow Naofumi's party to the location. Suddenly, black sludge oozes out of Filo's body and crashing together with Gaelion's. Something black rushed out of Naofumi's shield and engulfed Gaelion. The party retreated from the cave as the sludge now took the form of a dragon. Despite having Sadeena's buff and using most of his shield skill, the enemy's attack is intense enough to hurt Naofumi. After Raphtalia, Ren and Sadeena's physical attacks failed to weaken Gaelion; Rat, Wyndia, and Melty casts cooperative water magic and effectively choke Gaelion. As everyone ganked on the weakened Gaelion, Wyndia approached him to get him back to his sense. Seeing an opportunity to kill a weaker enemy, Gaelion went to attack Wyndia but stopped when she ordered him to do so.

Chapter 8: Demon Dragon
The dragon turned out to be Wyndia's foster father. When Naofumi thought Wyndia's effort has been a success, Gaelion proceeds to attack her. Wyndia sense another, more sinister presence in Gaelion's body. It introduces itself as Demon Dragon from Kizuna's world who uses a compatible body and Filo as a power source. The Demon Dragon converses briefly with Naofumi and tells him an aspiration. Considered the aspiration as ridiculous, Naofumi decided to continue their fight. Raphtalia and Ren attack Gaelion to no avail because he is basically powered by Naofumi's shield of wrath. Naofumi then thought of intentionally fails the shield power up to weaken the dragon.

Chapter 9: Forced Power-Up
The Demon Dragon hacked the shield and upgrade it, preventing Naofumi's countermeasure and take over the shield control. the Demon Dragon keeps upgrading it over and over to the point of overpowering Naofumi's defense and tanking both Raphtalia and Ren easily. Naofumi switched the tactic to defense-ignoring and defense-rating attacks, but the dragon also anticipated such attacks by using a barrier skill. While keeping the dragon busy with Raphtalia and Ren, Naofumi and Sadeena use buffs on Atla and Eclair. Using the Hengen Muso style and enhanced by Descent of the Thunder God, they break Demon Dragon's barriers and landed a fatal blow to the dragon. The dragon lowers his defense to make Atla and Eclair's attacks less effective, but then Raphtalia and Ren use their pure attack power on him. After taken some damage, baby Gaelion came out from the body, along with the unconscious Filo. It turned out that the one in control of baby Gaelion's body is Wyndia's father when he telepathically talks to Naofumi. Without a host body, the Demon Dragon changed to Wrath Dragon and continues to fight. Sadeena, Melty, Wyndia and Gaelion uses a cooperative magic and successfully incapacitate the dragon, Atla took the core while the dragon is weakened and Raphtalia finishes it off.

Chapter 10: Purification
After the Demon Dragon has defeated, its consciousness retreats to Naofumi's shield. Filo and Gaelion's levels don't revert back, but Filo's curse from All Sacrifice Aura has gone. Naofumi orders Filo to level up to make up for her level drain, along with Melty who is currently under-leveled due to her business managing Eclair's territory.

Chapter 11: Perfect Hidden Justice
Naofumi went to Zeltoble's open coliseum with some slaves to give them real-world fighting experience. Naofumi then found out that Itsuki also participating in the coliseum and approaches him. As if he couldn't hear, Itsuki ignores Naofumi and Rishia and went off to fight in his match. In the fight, Itsuki did pretty well despite the small area was disadvantageous for a bow user, and also showed some trait uncharacteristically of him. After observing Itsuki for a while, Naofumi noticed that in battle, Itsuki responded to his opponent's words. Rishia volunteered to fight Itsuki in conjunction to Naofumi's plan to capture him. With the help of the Slave Trader, they then set up a fake underground tournament to lure Itsuki out. When the match started, Rishia asked Itsuki to listen to Naofumi and pointed at him. Noticing that Naofumi and Ren are there, Itsuki's expression grew grim.

Chapter 12: Justice vs. Justice
Itsuki accuses Naofumi of some wrongdoings and reveals that Witch is connected to the situation. Having enough talk, Itsuki fires his skill to Naofumi in the spectator seat. Despite the effort to protect the spectators, an arrow hit the announcer. After being hit, the announcer's eyes had a crazy look and then he exposes Naofumi's plan. Itsuki tells that Witch give him the arrow to liberate people from brainwash. Rishia uses Muso Activation and starts to fight Itsuki, but he ignores her and focus on attacking Naofumi. Naofumi promises to fight Itsuki if he can defeat Rishia. Itsuki activates his cursed weapon skills to focus on defeating Rishia, but Rishia still has the upper hand. At the height of the fight, Rishia's reaper is broken. Itsuki's legendary bow fires a shot that gives Rishia a certain set of weapons to defeat Itsuki. After Itsuki's defeat, the announcer that hit by the cursed arrow is back to normal. Naofumi then offers Itsuki to show him the Witch's true nature, and he agreed to take Naofumi to the hideout.

Chapter 13: Atonement
By the time Itsuki arrived, Witch already escaped. She left some promissory debt notes, stamped with Itsuki's seal. After realizing the situation he is in, Itsuki fell to his knees. Rishia getting through to him and tells him that the world still needs him. Itsuki then started to make sobbing sounds, his cursed bow broke apart and then he collapsed. After calculating how to pay it off, Naofumi orders that Itsuki's debts to be transferred to him. Everyone then went back to the village, bringing the collapsed Itsuki along. The search for Witch ended in failure. Apparently the usage of Justice Bow took Itsuki's volition, making him unable to make a decision by himself. He then apologizes to Rishia for everything.

Chapter 14: Secret Base
Several days after Itsuki arrived at the village, Naofumi asked Sadeena to teach him the Way of the Dragon Vein, but Sadeena suggested to learn from Gaelion as well. Old Gaelion inside baby Gaelion's body now can openly talk because Wyndia isn't around. Naofumi considers that the village isn't favorable for the training, so Sadeena offered him to train in her secret base. After hours of learning the principle and observing Gaelion and Sadeena's demonstrations, Naofumi succeeded in his first use of the Way of Dragon Vein spell. They went to drink after the training sessions. When Raphtalia and Gaelion are passed out drunk, Sadeena starts a serious conversation. She reveals that Raphtalia hails from an isolationist region where Holy Heroes legend doesn't exist. Since Raphtalia is a descendant of a worshipped lineage, getting intimate with her might upset the country. Unless Naofumi is willing to commit to sticking by Raphtalia until the very end, Sadeena suggested him to avoid romantic relationship.

Chapter 15: Form is Emptiness
Two days after the talk with Sadeena, the weapon shop guy visit the village. He handed the miko outfit Naofumi ordered for Raphtalia. Later at night, after seeing Raphtalia's outfit, Sadeena quickly tries to undress her. Baffled by the situation, Naofumi orders Raphtalia to change in order to calm Sadeena down. Sadeena then explained that this particular outfit signifies a right to the throne in her country. All of a sudden, the house that Raphtalia had gone in to change clothes went ablaze, and a group of people appears out of nowhere to attack her. The residents are now aware of the assault and fight back, but the enemies showed no sign of retreating. The enemies turned out to be so strong that even the combined efforts of the village's residents can't put them to submission. Naofumi and Raphtalia then performed cooperative magic, causing sensory confusion on the enemies. Seizing the opportunity, everyone mustered a combined finisher technique with Raphtalia's new attack and successfully incapacitate all the enemies at once. Naofumi tried to interrogate the enemy, but all of them blew themselves up. The weapon shop guy seems to recognize the enemy's weapons but doesn't talk about what he knew and asked Naofumi's permission to do further inspection. After hearing Sadeena's explanation on how Q'ten Lo, Raphtalia's home country simply observed Raphtalia's suffering, Naofumi made up his mind to invade the country.