Mercy of the Dragon is a short story published in The Primarchs series that was originally part of an anthology. Mercy of the Dragon was first published as part of the Sons of the Emperor anthology in February 2018. The cover image used is that of Sons of the Emperor, as Mercy of the Dragon has yet to be published separately.
As the Emperor comes to Nocturne in the guise of the Outlander, He tells Vulkan of his destiny in the stars as one of His Primarchs. But the Lord of Drakes is hesitant to leave his world unprotected and so the Emperor must convince him of the worthiness of His Crusade.
- Sons of the Emperor (Anthology), "Mercy of the Dragon" (Anthology Short Story) by Nick Kyme