Fifth Pillar arc

The Fifth Pillar arc is the ninth story arc of the Fire Force manga series. Focusing on the awakening of another user of the Adolla Burst and Adolla Link. The strangely empowered Inca finds herself caught between Special Fire Force Company 8 and the Ash Flame Chivalric Order. With Shinra Kusakabe coming into conflict with Charon and Company 8 attempting prevent an Infernal Outbreak.

Danger Begins
After a successful outing, extorting an old man in exchange for saving his life, Inca, Panda and Sancho divide up their earnings. The three 'fire thieves' also discuss Inca's strange ability to predict fires through her sense of smell, which Inca claims is a sign she is part of the Fourth Generation. While discussing her desire to live dangerously, Inca briefly sees the ghostly Hitohashira Me, who warns Inca that a danger so great in will make Inca fall in love. Meanwhile, Captain Akitaru and Shinra discuss the possibility of another user of the Adolla Burst appearing and Hitohashira Me tells Shinra that the 'Fifth Pillar' is about to be born.

Inca looks upon Tokyo and sees that many fires are going to break out across the city. As these fires being, a number of Infernals appear as well. Resulting in Company 8 mobilising. While traveling in the Matchbox, the Company discusses Inca's reputation and bizarre power, coming to the conclusion that she might be the new user of the Adolla. Company 8 use Maki's Iron Owls to scan the area from above and see both the spread of the flames and the number of Infernals. With a minimum of 8 Infernals, Akitaru concludes that the Ash Flame Chivalric Order are using the Bugs in order to create this disaster. As a result, Company 8 spread out to control the situation to the best of their abilities. While the majority of the Company aid the evacuation and destroy the Infernals, Shinra is sent to find Inca and the White Hoods while Arthur is sent deal with Haumea if she appears.

Akitaru's suspicions are justified as Haumea is within the chaos. Using her electrical signals to locate Inca in a nearby park and directs Charon and his men towards their target. Sancho and Panda's attempts to stop Inca from endangering herself are interrupted by Charon appearing behind them. During his attempt to convince Inca to leave with him, Charon responds to Sancho grabbing his shoulder by blasting a hole through his chest. In the stress of seeing her ally die in front of her, Inca's abilities begins to evolve. Allowing her to create explosions around Charon, creating an opportunity for her to lure her attacker away from Panda by escaping into the city.

Inca is backed into a conner by Charon and his men, only for Shinra to strike from above. Landing between the blindfolded zealot and the fire thief, Shinra promises the confused Inca that he will protect her. Inca views his statement with scepticism and contempt as Charon engages Shinra in combat. While Shirna's attack barely phase Charon, Charon's strikes prove to be utterly devastating to the Fire Soldier. Eventually, Inca chooses to view both fighters as her opposition and unleases a mass of chaotic explosions to flee from them. Shinra moves to give chase, only for Charon to focus on him. Charon sends two of his followers after Inca while he and the rest move to capture Shinra, who has been declared the 'Fourth Piller' and is deemed necessary for the Preacher's plan.

Containing the Outbreak
While Akitaru has manages to defeat 3 Infernals, Vulcan confirms that their numbers are rapidly growing as the result of the White Hood's attempts to find a new host of the Adolla through the Bugs. The battle escalates, forcing Vulcan can defend himself from a surprise attack and pushes Hinawa into shooting the Infernal before Sister Iris can recite the traditional prayer. Maki is able to spot Haumea on a nearby rooftop and directs Arthur towards his target.

Hinawa and Vulcan move through the streets to confront a mass of Infernals, only to be confronted by a Demon. Vulcan calls for assistance but Akitaru and Iris are too far away. As a result, Tamaki appears dressed as a nun in order to recite the prayers and Karim from Company 1 arrives to aid them further. He does this by freezing the hoard of Infernals using his Thermoacoustic Refrigeration. Shinra receives help from Company 5's Tōru Kishiri and Company 2's Takeru Noto, who free him from the White Hood's grasp and allow him to chase after Inca. Shinra's flight is interrupted when Charon grabs him out of the air and slams he through a wall. The two struggle and Shinra is able to knock Charon through another wall and onto another rooftop. Before they can reengage, Shinra looks down and sees Inca struggling against the agents holding her down and refuses Shinra's help.

Akitaru and Iris make contact with members of Companies 1, 2 and 5. Meanwhile Arthur begins to battle against Haumea. This causes Haumea to order Charon to move quickly so they can escape. During her battle with Arthur, Haumea reveals there are meant to be Eight Pillars of the Adolla Burst that the White Hoods are trying to control.

Charon knocks Shinra down into the street and continuing their fight. With his high-speed attacks failing to work, Shinra decides to attempt to create an explosive attack using the Sing of Horns. In an attempt to understand what Charon's ability is, Shinra examines his style of counter attacks and realises that Charon is actually a member of the Second Generation. This ability allows Charon to harmlessly absorb kinetic energy and release it as explosive force. Shinra initially attempts to avoid hitting Charon, but the martial artist orders his followers to beat him until he has enough energy to produce a blast that brings Shinra to his knees. While collapsing, Shinra realises that Charon cannot release and absorb energy at the same time: meaning he is briefly vulnerable to a counter attack. With this knowledge, Reinvigorated, Shinra engages Charon for the final time and after multiple failed attempts combines his Rapid with the Sign of the Horn to blast Charon skywards with Hellfire. Despite being injured, Charon rises up and continues to fight and his men maintain the hold over Inca.

While Shinra's battle continues, Licht realises that the only way to destroy the Demon Infernal is to create a massive explosion. With nobody having the power to individually create such a blast, Licht creates a plan to resolve the situation and put out the surrounding fires through teamwork. The Second Generation members of the Fire Force use their abilities and the winds flowing into the town centre to pull the city's fires into a single location, creating a Firestorm that Maki is able to control. Vulcan and Akitaru manage to force the Demon into the vortex and Hinawa fire a mortar shell into the storm. Using the heat surrounding his attack to increase its power, Hinawa's attack instantly destroys the Demon upon impact. Before Maki loses control of the Firestorm, Karim is able to freeze the storm instantly. Through Licht's plan the alliance is able to destroy their opponent and save the citizens in a single stroke.

Haumea orders Charon to retreat with Inca as the Fire Force will be momentarily occupied, before leaping away from Arthur and using magnetism to slow her descent. Before he can leave, Charon is confronted by Shinra. Shinra demands Inca's release but realises that his counter attack will be less effective as Charon is aware of it. Instead, he asks Inca to free herself using her ability. However, Inca hesitate and struggles between choosing whether to live safely under Fire Force protection or to let the White Hoods take her. Realising that she would experience more danger siding with Charon and Shinra would continue to chase after her, Inca chooses to freely join with Haumea's group. Leaving Shinra defeated in the street, Inca meets with Haumea. Before they can leave, Panda arrives with a hand gun and attempts to save Inca. Seeing that her abilities are active again, Inca sets her old friend on fire, leaving him to die while leaving with Charon and Haumea.