Cruel Dragon Arc

The Cruel Dragon Arc is the eighteenth arc of the series, and the third arc of the Neo Heroes Saga.

Plot
Saitama accidentally gets into a conflict between two groups known as the Saints and Deathbone. After Saitama defeats Rangor, one of the nine warriors of the Dragon Alliance and an ally of Deathbone, warriors of the Saints express their gratitude to him before telling him a story regarding Cruel Dragon, an ancient creature that once wreaked havoc on humanity a long time ago before being sealed by a group of ancient soldiers using nine sealing orbs. In order to prevent Cruel Dragon from resurrecting, warriors of the Saints were entrusted to guard the nine sealing stones that if collected altogether would break the seal and release the ancient dragon. In contrast, Deathbone, a cult in which its people believe themselves to be dragon-born, thirsted for the dragon's resurrection and humanity's destruction, leading to the two groups fighting over the nine sealing stones. The two groups have been in conflict for 800 years, but Deathbone recently increased their activity, taking advantage of the recent frequent monster incidents. One of the Saints warriors holds down a member of Deathbone, who begins to monologue as he loses consciousness, that Deathbone will not stop until the day Cruel Dragon will eventually be revived and humanity shall come to an end, until Saitama throws a bucket of water on his face. Saitama then decides that instead of waiting any longer, the dragon can be freed right now to finish it off once and for all. Much to the Saints' dismay, Saitama picks up the Deathbone member who helps him locate all nine seals, and flees from the Saint members chasing after him. Before long, Saitama collects all the nine stones and a summoning ceremony is performed by the Deathbone member. More warriors of the Saints arrive at their place in an attempt to stop them, only to see that they are too late as Cruel Dragon has been unsealed after centuries of imprisonment. Upon being revived, Cruel Dragon declares its intention to destroy humanity before attacking Saitama. However, the dragon soon meets its demise as Saitama casually destroys it like most monsters he has encountered, much to the shock of the Deathbone member and the delight of the Saints warriors.

Story Impact

 * Saitama has new experiences in his life, such as the existence of seal stones and cults. When playing video games with King soon after at his apartment, he tells King that he thought such things only existed in games and mangas, and admits that there are many things in the world he does not know of.