Deltarune Chapter 3 Secret Boss Location And How To Unlock It

Deltarune Chapter 3 continues Toby Fox's tradition of hiding powerful optional bosses behind intricate gameplay mechanics and multi-step side quests. Finding the secret boss in this chapter requires precision across mini-games, tracking down key items, and preparing for a climax that tests your combat mastery.

Achieving S Rank in TV Time Boards

Unlocking the path to the optional encounter begins early in the chapter with the TV Time minigame boards. Players must score an S Rank on both board sections or utilize designated NPCs to secure access to restricted backrooms.

Passing through the changing room door grants access to a strange retro game world that must be visited across three distinct chapter phases. Completing these visits ensures you progress the hidden storyline required to reach the boss.

Obtaining the Shadow Mantle

During your third visit to the hidden game area, a shadow mini-boss will challenge your party in combat. Defeating this shadow creature rewards you with the Shadow Mantle, an essential armor piece for surviving the ultimate encounter.

Equipping the Shadow Mantle heavily reduces elemental damage type attacks, giving your team a crucial defensive advantage. Without this item, standing against the chapter's final secret foe becomes nearly impossible.

Confronting the Roaring Knight

After acquiring the mantle, continue playing through the chapter's main storyline until the final sequence. Following the primary boss encounter, the Roaring Knight interrupts the narrative to initiate the secret battle.

This confrontation demands heavy TP management, relying on Susie's Rude Buster and strategic defenses to win. Claiming victory rewards players with top-tier equipment and another Shadow Crystal for their collection.