I've been working on the lore for my Nighthaunt army, the Congregation of the Crimson Shroud. Korak the Grim is one of my oldest characters, dating back to my 5th Edition Warhammer Fantasy Undead army. His story is a long one, and now it continues into the Age of Sigmar...
Korak remembered the sky turning to blood, the ground roiling like the sea. He had flown to the top of the citadel, which –somehow– still stood amid the crashing waves of carnage. At the tower's parapet he found his master, Nieman Kimmel. The necromancer was gesturing wildly to the air, saying something that Korak couldn't quite make out over the cacophony of the world ending. At first, Korak had thought that Kimmel was invoking an incantation that might stop the Storm of Chaos, but he soon realized that the necromancer was simply pointing to the sky where the warp moon used to be... and laughing.
Time had little meaning to Korak the Grim. The wraith was beyond death... The past, the future, it was all the same to him. His years as a mortal man were but a drop in an endless ocean of eternity. Eons in the void passed without measure, every moment focused on his burning hatred of the living.
After experiencing nothing for so long, Korak experienced... something. Like a shipwrecked sailor washing ashore, he was brought to the sands of Shyish on the wave of death magic that was released by the great necroquake. Souls were everywhere in this new realm, and with the Crimson Reapers again by his side, Korak began the grim task of harvesting them. Some souls he recognized from a time long ago, and he still held dominion over them– Banshees and other wraiths. Korak assigned them as jailors and lieutenants to oversee his growing congregation. One soul in particular was absent, however– that of his former master. If Nieman Kimmel's immortal soul had survived beyond the void, Korak would find it.
The Crimson Reapers
The souls of the Crimson Reapers have been shackled to the will of Korak the Grim since long before the Age of Myth. Their servitude dates back to the World That Was, when they still had physical forms– A skeletal legion, the population of an entire village slain and bound to do the bidding of the Red-Hooded Wraith. Eons of time could not sever his hold over their eternal souls, and as Korak materialized in the Realm of Shyish, so too did his dreaded Crimson Reapers.
The Crimson Reapers was the first named unit that I had built for my Warhammer collection, more than 20 years ago. So, it's only fitting that they form the core of my Nighthaunt army in the Age of Sigmar.
The other units and characters are shaping up as well. Some units, like the Shadowriders of Shyish are finished. Those Hexwraiths were the result of such involved conversions, that I'll never expand their numbers. If I ever add more Hexwraiths, they will be a different style, to distinguish them as a separate unit. Other units like the Glaivewraith Stalkers are just getting started, and will receive reinforcements soon.