Editing Warhammer 40,000/9th Edition Tactics/Chaos Daemons (section)

=== CSM ===
The obvious choice for both fluff and functionality.  Aside from the obvious souping perks, CSM also have a lot of the heavy shooting Daemons don't have, with Havocs providing cheap fire support, Predators for dealing with infantry and tanks depending on loadout, Fiends having either big scary guns or big meaty claws to spook heavy infantry and armor, Obliterators for a crippling mass of fire from out of nowhere, and lastly Defilers for being better than Soul Grinders in every conceivable way.  Cultists also give you a cheap fodder unit to camp objectives and hold angles while your blocks of daemon troops are busy [[/tg/_gets_shit_done|getting shit done]].  Rhinos are also a nice thing to grab since they can block enemy LOS and allow your squishier daemons like Bloodletters or Daemonettes to run from cover to cover and set up charges unmolested.
*Seriously, the buffs Defilers have had through the edition change and FAQ put Soul Grinders to ''shame'', since they're so much cheaper base, can take heavier or punchier weapons, AND have a (albeit CP-intensive) method of gaining full rerolls.  The only thing that sets the Grinders apart is their daemon allegiance, but even then the amount of overpay for a unit that's permanently stuck between trying to shoot things and trying to punch things makes it not all that worthwhile by comparison.
*Night Lords are ironically very powerful allies to attach Daemons to thanks to all their Leadership bomb abilities. With the improved perks of Manifestation, you can have them deep strike much closer to the enemies through strategic Strat spam and getting a Warp Locus in there.


Of course, these all involve attaching Daemons as allies. Using CSM as the allies throws this all off due to loss of any faction bonuses. Regardless of who allies to who, you'll have to grapple with the issues of no keyword synergy, as now Daemons have a different keyword than the marines, and thus you can't have your DPs benefit both mortal and daemon units or have your greater daemons boost your cultists.