A new faction is hitting tabletops soon. They're the Riftforged Orcs and Mantic is giving them a bit of an introduction and background check in this new article.
From the article:
Thunderbolt and lightning, very very frightening for Pannithor! The Riftforged orcs are almost here and all this week on the blog we’re exploring this awesome new army list in more detail. You’ll be able to find out about the key units, how they play and the design philosophy behind these powerful new orcs. But first of all, let’s find out a little more about the lore of the Riftforged. Is their only motivation to smash stuff to pieces like a giant, angry toddler? Well, yes, it is… but surely there’s more to it than that?
Basically, it’s all Dravak Dalkan’s fault. When that pesky Abyssal Dwarf ironcaster opened up the rift beneath the Halpi Mountains, it caused all sorts of dangerous magic to swirl around Pannithor. At the height of the Nexus’ surge of energy, before the forces of good pushed back the armies of evil, there came a moment when the Southern Rift and the Abyss were infused with such power that the veil tore entirely, and the two pits of darkness were linked as one beneath Pannithor. At such an unholy coupling, Oskan (one of the Wicked Ones) himself saw that the time had come to herald in a new age of darkness. Oskan summoned Garkan (the original creator of the orcs and goblins), and together they formulated a plan to destroy all that was good in the world. Garkan harnessed the power of the violent, unnatural storms that raged across the world above, the flesh forges of the Fourth Circle came alive with energy hitherto unseen, and the souls of the tormented cried out in anguish.