There are certain figures and armies in Age of Sigmar that you're supposed to get your opponent's permission before you play them. They're the bit more edge-case armies and models that maybe didn't get the same level of testing. Well, some of those figures and armies have been vetted and now can be used whenever. Have yourselves a look.
From the article:
There’s exciting news today for fans of the Mortal Realms, with an update direct from the Warhammer Studio on the topic of Legendary Battalions presented in the Tome Celestial!
If you’re not familiar with the Tome Celestial, it’s a recurring White Dwarf feature which shines a spotlight on a particular force or faction from Warhammer Age of Sigmar. You could think of it as a mini-battletome that delves into new detail. These have covered awesome topics such as the Steel Souls Stormcast Eternals, the Vostarg Lodge of the Fyreslayers, and the Host of Syll’Esske – to name but three.