Destruction of Asur
By the end of the Fall of the Eldar, N'Kari took part in the destruction of Asur, the first Aspect Shrine where Asurmen taught the Asuryani Path. There N'Kari killed the original Phoenix Lord of the Dire Avengers. Drastanta, Tempest of Starlight, the Phoenix Lord of the Shining Spears, found Asurmen too late to save his mentor's life. Keening with rage and sorrow, Drastanta slew the daemon, the energies of his Celestial Lance shattering the creature's vile spirit and sending him keening back into the Warp.
Battle of Calth
Sometime during the 41st Millennium N'Kari was encountered upon the Imperial Agri-World of Gheistos, during the so-called Gheistos Cataclysm. N'Kari led a daemonic army of Fiends and Daemonettes, and his arrival marked the birth of an alliance between Nurgle's Great Unclean One Ku'gath the Plague Father and Slaanesh.
The Battle of the Ghost Halls
N'Kari was next encountered by a Grey Knights strike force in the 800s.M41, upon the desolate Aeldari Craftworld of Malan'tai. The Chapter's Prognosticars had received particularly dire visions of an impending daemonic incursion and so they despatched a strike force to a point in space where no worlds were known to exist.
On arrival, the strike force encountered the massive, bio-acid-scorched hulk of Craftworld Malan'tai. Though its inhabitants had all been destroyed in an assault by the Tyranids in 459.812.M41, Malan'tai was not as empty as it first appeared. N'Kari and his ilk stalked the devastated world, seeking hidden caches of Eldar Spirit Stones and the souls within to consume. With each Spirit Stone consumed the might of N'Kari increased, and by the time the Grey Knights arrived, his power had increased tenfold, the beast having only feasted on but a fraction of the souls to be found within the Craftworld's vaults. Ordinarily, to fight such a foe would be beyond even the Grey Knights, but the wisdom of the Prognosticars prevailed, as they had bid Captain Pelenas, who commanded the Grey Knights force, to take as many Purifiers as would go.
The Purifiers led the charge as the Grey Knights launched their assault on N'Kari and his daemonic host. The consecrated flame of their Incinerators preceded their advance. The cleansing azure flames roared through the halls like a hungry spirit, consuming the daemons in its path, leaving those hellspawn that survived as ripe prey for the advancing Grey Knights.
The Keeper of Secrets was finally cornered within the shattered remnants of the Craftworld's Dome of Crystal Seers. The daemon fought with drunken fury -- in a matter of moments his spear claimed the lives of a dozen Purifiers as well as striking down Pelenas. Yet, before the Greater Daemon could strike the killing blow, Justicar Anval Thawn threw himself into the path of N'Kari's spear and was laid low in his Captain's place. With N'Kari's weapon momentarily trapped in the prison of Thawn's flesh, the surviving Purifiers were able to complete the ritual of Twelve Bloody Swords, draining N'Kari of his stolen power, leaving him vulnerable to Pelenas' death blow and banishing him back to the Warp once more.
Battle of Jostero
At an unknown date, N'Kari and the Prophet of Jostero forged an alliance, and he drew a portion of the Realm of Chaos into the mortal world, pulling Supreme Grand Master of the Grey Knights Kaldor Draigo through along with it. Draigo was thus briefly reunited with his Chapter once more, for a Brotherhood of the Grey Knights had arrived on Jostero to combat N'Kari's threat.
Draigo had been long adrift in time, for he knew these warriors not, yet they embraced him as their brother, and they fought side-by-side to cast down the mad Prophet of Jostero and banish his daemonic allies. But Draigo's victory ultimately proved a hollow one, for when the gateway into the Warp closed, the Grey Knight found himself drawn back through the rift and trapped again within the Realm of Chaos.
Older background material states that N'Kari was a Daemon Prince of Slaanesh. He had been born on an isolated, backwater planet which had been trapped within the epicentre of a violent Warp Storm for millennia. The Forces of Chaos had repeatedly attempted to conquer this world and claim it as their prize. But their attempts had been thwarted by the faithful and uncorrupted populace.
During one of these Chaos incursions N'Kari had risen to prominence upon the benighted world. He proved himself to be a dedicated follower of the Dark Prince, earning the blessing of his patron god with his uncounted victories in battle and the inevitable debauchery and disgusting Slaaneshi orgies that preceded them.
He was rewarded with the gift of daemonhood. Along with the infamous Daemon Prince Doombreed, N'Kari confronted the Emperor of Mankind when he teleported aboard the Warmaster Horus' Battle Barge Vengeful Spirit during the Battle of Terra that brought the Horus Heresy to a close. From that bygone age, N'Kari continued to serve the Lord of Pleasure into the present era of the galaxy's history.
Also, in Codex: Grey Knights (5th Edition), the battle between the Grey Knights and N'Kari within the deserted Craftworld of Malan'tai is stated to take place in 800.M41, but Codex: Tyranids (5th Edition) explicitly says its Eldar population was not killed until 459.812.M41.
- Codex: Chaos (2nd Edition), pg. 140
- Battle Missions (5th Edition), pg. 17
- Codex: Grey Knights (5th Edition), pp. 14, 39
- Codex: Tyranids (5th Edition), pg. 58
- Iyanden: A Codex: Eldar Supplement (6th Edition) (Digital Edition), pg. 83
- Know No Fear (Novel) by Dan Abnett, pp. 284, 345-347