Overlord III will stream in Japanese on Crunchyroll and with an English dub via Funimation.
Here’s how the Crunch describes Overlord’s first season:
When a popular MMORPG is scheduled to be shut down permanently, veteran player Momonga refuses to log out. As NPCs begin to develop personalities and minds of their own he decides to put his skills to use as the game’s new overlord.
Source: Anime Anime