News about several sightings of an Armor Giant somewhere in Ordan Forest reaches Helbram, who quickly sends Dawn Roar, an elite group of Holy Knights, to search for the Armor Giant. Meanwhile, Guila visits her younger brother Zeal, and she later kills three thugs who bullied him for his spare change. Meliodas and his friends split up in the nearby village. Elizabeth and Hawk encounter a boy named Alan, who is looking for some glue to repair armor. Upon hearing the low growls that echo in the forest, Meliodas, Ban and King find the Armor Giant being surrounded by Dawn Roar, but Meliodas, Ban and King are no match against Dawn Roar. Just as it seems that the Armor Giant is about to be slain, Alan intercepts and reveals himself as Gowther, the Goat's Sin of Lust.

Gowther gives the head of the Armor Giant to the members of Dawn Roar in order to convince them to withdraw from battle. However, the demon breaks through the armor and attacks Meliodas, Ban, King and Gowther. Meliodas lowers his guard upon noticing a Holy Knight merged into the demon's chest, but Gowther uses his Sacred Treasure, the Twin Bow Herritt, to stop the demon. Meanwhile, Cain visits Elizabeth in the Boar Hat, where he tells her the story of Liz, a knight from an enemy kingdom who became Meliodas's past lover after he saved her from being sentenced to death. Ban gouges out the heart of the Holy Knight, recognized as Guila's father Dale, yet the demon still remains alive. Elizabeth rushes to Meliodas and gives him Liz's sword left behind, which allows him to destroy the demon. It is realized that Dale was one of Hendrickson's failed demon experiments.

Ban attempts to kill Meliodas, but is stopped by Hawk. Meliodas and the sins corner Hendriksen and prepare to take him down.

Hendrickson unveils the source of his power, the corpse of a red demon, which is the same one that Ban slayed in the Fairy King's Forest long ago. After Ban pummels Hendrickson through the ground, Meliodas, Ban, King and Gowther jump down the hole to a cave, where Hendrickson injects himself with the blood from the corpse of a gray demon to acquire even more power. A sudden burst of energy from Hendrickson sends the four of them back above ground, where Hendrickson easily overpowers all of his opponents despite all of their efforts. With Meliodas left standing and protecting Elizabeth, Hendrickson casts a large dark blast, but Hawk sacrifices himself in order to save the two of them. Shocked of losing her dear friend, Elizabeth awakens her dormant powers that repels Hendrickson and heals everyone else. However, Hendrickson survives and still has strength left in him to fight.

Ban and Meliodas meet to continue the duel they left unfinished before, only to find that Hawk has told everyone about their solemn battle.

Diane confronts Gowther after he manipulates Guila and Zeal's memories. With the return of the Demon Clan, new threats descend upon allied clans.

King struggles to fend off the giant Albion sent to destroy the Fairy King's Forest. Galand of the Ten Commandments appears before Meliodas.

The fairies reconcile their differences with King as Ban leaves the forest. Meanwhile, Meliodas and gang are overwhelmed by the sheer power of Galand.

Hendrickson, thought to have been defeated against Meliodas, aids Gilthunder and the Holy Knights against a powerful Gray Demon.