The big releases for April coming out of Games Workshop for the Age of Sigmar will center around the Kharadron Overlords, but we will also see a new Battletome for Khorne equivalent to the Disciples of Tzeentch we saw previously.
via Warhammer Community
https://www.warhammer-community.com/2017/03/19/coming-to-the-mortal-realms-this-april/
Blades of Khorne
- The forces of Chaos will be getting some new rules with a the new ‘Chaos Battletome: Blades of Khorne
- In many ways, the new Battletome is the Khornate equivalent of the Disciples of Tzeentch book we saw in January.
- There are no new models to accompany the release
Kharadron Overlords
- The other big release of April is the Kharadron Overlords.