It seems that access to the new Khorn Daemonkin codex has been made, and now we have some insight to what is actually in it. For one, Kharn is not there, but Beserkers are. Following are some of the army wide rules, detachments, and artifacts......
I have to say that this may be my favorite codex cover so far.
Please realize that the codex has not been released, so take these with a little room for error like always, until we have an official release.
via Iuchiban on Warseer
http://www.warseer.com/forums/showthread.php?406739-Codex-Khorne-Daemonkin/page11
Kharn is NOT in the codex but Bezerkers are.
The main rule of the codex is "Blood for the blood good":
You get "blood points for every unit you destroy and for every unit you are destroyed. Carachters slained in challenges generate blood points as well.
At the beginning of your turn you can spend those blood points (effects lasts till the beginning of your next turn)
1 Adamantium will
2 Rage + Furious Charge
3 Feel no pain
4 +1A
5 Summon 8 bloodletters of 5 Flesh hounds
6 Summon 3 Bloodcrushers or one Skull cannon
7 One carácter becomes a Demon Prince (LD test, if failed becomes a Spawn instead)
8 One carácter becomes a Bloodthirster (Same as above)
Once you spend a blood points you loose them all. For example if you have 5 and spend 4 for Feel No Pain, the left point is lost.
Artifacts are:
-One Axe that you have to count the wounds infflicted with it:
1-2 +1S
3-4 Rampage
5-7 Sx2
8+ Instant Death
Effects are acumulative
-One armour that gives you 3+, Feel no Pain and Eternal warrior
-One Rune that gives bearer adamantium will, and you can explode it. If so, till your next turn, in a 24" bubble, all pyshic test get perils with any doublé
-One Sword that gives you a blood point for every wound
-One helmet that gives you fear and any 6 to hit generates an additional attack
-One Axe that when bearer dies becomes a Bloodthirster but and the end your turn loses D3 wounds (Only inv saves allowed)
Detachments
There is Detachment similar to the Decurion: The Blood host
Mandatory: Slaughter cult (1 HQ, 2-8 Bezerkers, Bloodletters or Chaos Space Marines in any combination), 1-4 Possessed, 0-2 Spawn units, 0-2 Cultits
Benefits: Reroll Warlord trait and generates 1 Blood point every turn. When spending blood points you can for free get another bonus with less value than the first one.
Then optional:
Lord of Slaughter: 1 BT
Brazen Onslaught: 1-4 units of Termis, 2-4 units of Bloodcrushers (+1A in CaC if opponent has more models in that combat)
Khorne Bloodstorm: 2-4 units of Raptors, 1-4 units of Warp Talons, 0-1 Helldrake (+1S of HoW attacks)
Gorepack: 2-4 Chaos Bikers, 1-4 Fleshhounds (Fleshhouds get HoW, and Bikers reroll to wound their HoW attacks
Charnel Cohort: 1 HQ (not a BT), 2-8 Bloodletters, 1-4 Fleshhounds, 1-4 Bloodcrushers, 0-4 Skull Cannon (Fear tests with -2LD, if HQ is in reserves may reroll to enter the battle. Other units do not scatter if enter reserves at 6" of the HQ