The afterword to the second part of the 16th volume of Kugane Maruyama 's light novel , Overlord , revealed that it will conclude in two volumes.
Synopsis
Yggdrasil is a popular online game that suddenly has its servers shut down. Momonga, a young player, decides not to log out and is transformed into a skeleton, the Overlord. Having no family, friends, or place in real society, young Momonga decides to fight to dominate the new world the game has become.
Kugane Maruyama began the original light novel series online in 2010, and Kadokawa 's Enterbrain began publishing the print series with illustrations by so-bin in 2012.
Source: ANN