Return to Demon Castle Arc

Twelfth in the webtoon's run, this arc spans novel Chapters 93 to 110, webtoon Chapters 76 to 89, and anime Episodes 18 to 21. It is positioned after the Hunters Guild Gate Arc and ahead of the Jeju Island Arc. Jinwoo heads once more into the Demon Castle, this time chasing the final component he needs to finish the Holy Water of Life. Partway through he encounters Esil Radiru, a cordial demon noble who proposes leading him to Baran, the castle's ruling king and ultimate boss, on the condition that he spares her clan.

Inside the castle the two strike their bargain, and Jinwoo holds to it by letting Esil live. The climactic confrontation pits him against both Baran and the beast Kaisellin, a fight that ends with the pair of them slain. Before that, he openly puts his strength on display for three figures, Baek Yoonho among them alongside Choi Jong-In and chairman Go Gunhee, and word that he has formally reached S-Rank spreads around the globe. The arc keeps the human-side plot moving as well: Lee Minsung gains official A-Rank recognition, Jinwoo resolves to found his own guild and invites Yoo Jinho to serve as Vice Guild Master, and Baek Yoonho grasps that Jinwoo is a hunter whose growth never stops.

Other threads thicken the wider story. Yoo Myunghan receives a diagnosis of Eternal Slumber Disease, a mutated Ant manages to reach South Korea, and Jinwoo's shadows advance in rank, with Igris rising to Elite-Knight and a Shadow Monster becoming a Knight under the name Tank. Goto Ryuji also lands in Korea to set up the fourth Jeju Island Raid. The differences between formats are noted too: in the novel Esil departs for her own floor once they hit the ninety-ninth level, and there Jinwoo overcomes Baran with far less struggle than in the webtoon.

Defeating Baran carries Jinwoo up to level 97 and hands him a haul of treasures. Among them are the Demon Monarch's Ring and the Demon King's Longsword, plus the blade set called the Daggers of the Demon King and a vial holding the ruler's blood in purified form. With these in hand he brews six bottles of the Holy Water of Life. He also pulls out Kaisellin's shadow and christens it Kaisel, acquires the Shadow Exchange skill, and is awarded the Demon Hunter title, all of which propel him toward the Jeju Island Arc.