Emilia and Subaru manage to defeat Regulus Corneas, the Archbishop of Greed, through a combined strategy. The key lies in uncovering his weakness: his invulnerability is tied to the hearts of his wives, whom he abuses as "protective vessels" for his own heart. Emilia convinces the women—led by Sylphy (No. 184)—to rise against Regulus. When they attempt to take their own lives with shards of glass, Emilia freezes them to stop their hearts. This forces Regulus's heart to flee into Emilia's body.

Meanwhile, Subaru stalls Regulus by feigning weakness and luring him into arrogant monologues. Emilia trusts Subaru blindly as he uses the "Unseen Hand" (an ability inherited from Petelgeuse) to tear Regulus's black heart from her chest and destroy it. With his invulnerability shattered, Emilia confronts Regulus with a giant ice hammer and delivers 53 blows—one for each oppressed wife.

Though Regulus attempts to protect his heart again, Reinhard returns after bouncing off the moon and being deliberately hurled back into the city. In a final duel, Reinhard ends Regulus with overwhelming strikes, banishing him into the depths of the town well.

Emilia frees the frozen women, who celebrate their freedom. Sylphy bursts into tears and embraces Emilia in gratitude. With Regulus's defeat, Subaru and Emilia find a brief respite, while the next conflict between Wilhelm and Theresia looms.