Mercedes and the Waning Moon

Cast out from vampire high society, Countess Mercedes could have plotted revenge. Instead, she turned her attention to the ruins beneath the world. A creature of centuries, she knows that power isn't always about strength. Sometimes it's about knowing which door to open and which to leave sealed.

Firehead's light novel series, brought to life by illustrator KeG, began as a web novel on Shōsetsuka ni Narō in October 2018 and ran through November 2022. TO Books picked it up for print, releasing the first volume in May 2021. Five volumes have been published as of July 2026. A manga adaptation by Pochi Edoya launched on TO Books's Comic Corona website in August 2021 and now spans six tankōbon volumes. Studio Teddy is producing an anime adaptation set to premiere in January 2027.

Mercedes assembles a motley crew of adventurers, each with their own baggage, to explore dungeons that are as much about history as they are about treasure. Her aristocratic upbringing gives her skills in negotiation and strategy that prove as vital as any sword. The series blends political intrigue among vampire nobles with classic dungeon crawling, offering a fresh take on the isekai formula. Fans of Mushoku Tensei or The Saga of Tanya the Evil will find familiar pleasures in its character-driven storytelling and detailed world-building.[edit]