Within the foggy, gothic expanse of Thriller Bark, Gecko Moria’s top commanders each control a specialized faction of the undead to maintain the island's terrifying reputation. Alongside Absalom, Perona, and Hogback, Nico Robin serves as the commander of the Relic Zombies. These are the reanimated corpses of ancient warriors, forgotten kings, and centuries-old scholars unearthed from the historical ruins plundered by the giant pirate ship.

Robin has converted the deep, subterranean catacombs of the mast-mansion into a massive, shadowy archive. While the other commanders use their forces for raw combat or cheap tricks, she utilizes her platoon to excavate, translate, and protect the lost history bound within the island's crypts. Her zombies are distinct, adorned in weathered, archaic armour, wrapped in ancient burial linens, and carrying a quiet, disciplined aura quite unlike the chaotic nature of the wild or surprise zombies.

The peace of her underground scriptorium is disrupted when an outsider slips past the upper defences, tumbling down into the cold, stone vaults. Rather than signalling for a full-scale island alert, Robin orders her silent, ancient guardians to surround the exit. She is far more interested in observing this unexpected guest herself, eager to see what kind of secrets or historical knowledge they might be carrying.