Take it for an objective-raiding, board-control army that punishes the enemy for approaching the objectives you already hold. It's strong into armies that must physically move onto your objectives (they eat D3 mortal wounds on a 2+), and great when you want Anhrathe units to make objectives sticky and then fade away. It rewards an Anhrathe/Corsair-heavy roster, since most bonuses key off the Anhrathe keyword. At 2 DP it leaves 1 DP for a support like Path of the Outcast.
Sample gameplan: grab midfield objectives early with Voidscarred (put Voidstone on a key holder for a 5++). Once you control them, Void Thieves keeps them yours even after your holders die, and Relentless Raiders chips D3 mortal wounds off every enemy that moves in. Use Yriel to hold units in Reserves and drop Voidreavers into the backfield; after they kill something, Into the Breach repositions them. On defence, layer Cloak and Shadow and Vengeful Sorrow to keep raiders alive, and Lethal Ruse to disengage and re-charge with a burst of mortal wounds.