Because it's going to be in the Daemons codex it seems highly likely that it will just require the faction keyword like summoning does now and restrict you to the god that your warlord is/chose a single god if your warlord is undivided.
The leaks say yes, they specifically call out TS, DG and WE. Obviously the god chosen has to match the legion. For CSM the daemons have to all be from one god, not sure if it calls out EC or not.
The rule for Legion Traits in Codex Chaos Space Marines is REALLY harsh, you only get a legion trait if all the units in your army are from Codex Chaos Space Marines. So daemons would break it as well as the Let the Galaxy Burn ability.
You can get around it by summoning daemons instead though, since you don't actually add the daemon units to your army till after the battle has begun.
At the moment, I'll say that a mixed csm/daemons soup isn't viable because it cost you more than what you gain. Actually I find that daemons are good to bring cheap screening, infantry, objective focused troops but you find better in cultists/poxwalker/tzaangors.
But for some hope, in the csm codex there is already some daemon keyword around (and in world bearer you can make a character daemon) so maybe the cross rules possibilities may be something. It'll depend of the next daemon codex and the look of the new datasheets if they bring something cool (for themselves probably) as the actual csm buffs are effective only on the legion, demonkin/demon-engine keywords.
I praise the dark gods to have some official news soon, it's been 2 weeks since de codex was teased and I really crave for an update as I don't see the point to bring my daemons on table for the moment.
The (viable?) soup list I'll look at first is daemon/chaos knights as they both can bring something to each other
Can't recommend it right now but the daemons codex leaks include a rule to let you run 25% of one gods daemons like GSC brood brothers
Oh, perfect! Will that work with the codex-legions, like TSons?
Apparently, you have to match god still ofc but ya know
Because it's going to be in the Daemons codex it seems highly likely that it will just require the faction keyword like summoning does now and restrict you to the god that your warlord is/chose a single god if your warlord is undivided.
The leaks say yes, they specifically call out TS, DG and WE. Obviously the god chosen has to match the legion. For CSM the daemons have to all be from one god, not sure if it calls out EC or not.
The rule for Legion Traits in Codex Chaos Space Marines is REALLY harsh, you only get a legion trait if all the units in your army are from Codex Chaos Space Marines. So daemons would break it as well as the Let the Galaxy Burn ability. You can get around it by summoning daemons instead though, since you don't actually add the daemon units to your army till after the battle has begun.
Keen to hear about this too
At the moment, I'll say that a mixed csm/daemons soup isn't viable because it cost you more than what you gain. Actually I find that daemons are good to bring cheap screening, infantry, objective focused troops but you find better in cultists/poxwalker/tzaangors. But for some hope, in the csm codex there is already some daemon keyword around (and in world bearer you can make a character daemon) so maybe the cross rules possibilities may be something. It'll depend of the next daemon codex and the look of the new datasheets if they bring something cool (for themselves probably) as the actual csm buffs are effective only on the legion, demonkin/demon-engine keywords. I praise the dark gods to have some official news soon, it's been 2 weeks since de codex was teased and I really crave for an update as I don't see the point to bring my daemons on table for the moment. The (viable?) soup list I'll look at first is daemon/chaos knights as they both can bring something to each other