The Emissary of the King is a side story in the Overlord series. It was released on September 25, 2015 in Box 1 of the Blu-ray & DVD Collection.
In order to better understand his new position as Overlord of the Great Tomb of Nazarick, Ainz sends out a Death Knight on an errand to find out the needs and desires of his subordinates.
Next to understand the desires of his subordinates, especially the Floor Guardians, Ainz decides to do a survey of each Guardian. Rather than go to them individually and attract unwanted attention, he summons a Death Knight to be his messenger.
After visiting Shalltear Bloodfallen's residence, the Death Knight reports, through mental link, to Ainz that the vampire wishes to have Ainz's love. Ainz embarrassed and unable to accept that answer decides to use his mistake with Shalltear to amend his questions for the rest of the Guardians.
Ainz directs the undead to the 5th Floor to see Cocytus. The warrior greets the Death Knight, and believing Ainz's query to be a test, answers that he wishes Ainz to produce an heir for the Great Tomb of Nazarick.
Leaving the Death Knight heads to the 6th Floor to see Aura Bella Fiora and Mare Bello Fiore. The twins are surprised by the undead, but welcome it after hearing it was sent by Ainz. Though confused by Ainz's questions they answer: Aura wishing to have a flying magical beast and Mare wants a plant creature to raise.
The Death Knight finally travels to Demiurge's domain on the 7th Floor. The demon thinks it to be a test of sort, but answers he has nothing he could want as he already has everything created by his creator. Before the undead leaves, the demon requests that once Ainz takes over the world, that Demiurge be given command over the sky. The Death Knight makes it reports to Ainz, satisfied with the survey. Seeing that Albedo to be the last one to question, he decides to do it personally. He is shocked to see that Albedo to be living in the throne room of Nazarick, as Tabula never assigned her quarters of her own. He then delegates one of the private guest suites on the 10th Floor for the Guardian Overseer's use.
At the end, Albedo is seen holding a tattered flag of the guild, Ainz Ooal Gown, cursing its name for its members abandoning them and taking the name of her lover.
- This is the only special, where a summoned monster like the Death Knight, has its own point of view narrated throughout the story, but without dialogues from it included.