Rules question - Belakor and master of possession

[Jack Shrapnel]

Alright... so the Disciples of Belakor allow you to put csm and daemons in the same detachment, with a ton of restrictions (no daemon engines, no special characters, no greater deamons, no world eaters, no tsons, no death guard, no chaos knights, no berzerkers, rubrics, plague marines or noise marines or any daemon princes. )

it says that any heretic astartes factions gain the "legion disciples" keyword and cannot have a legion trait, cannot use any legion specific strategim/relics/warlord/traits or psychic powers - only generic CSM / daemons one. 

The master of possession's spell cursed earth specifically says:

"The invulnerable save of friendly <LEGION> Daemon units is improved by 1"

now... the confusing part is:

A: Does this spell work AT ALL, because it doesn't say it replaces the keyword Legion with Legion Disciples, it just adds it... so technically they could add the legion keyword even if they don't use it. I think it still works as I believe you can still have <LEGION> with any csm. 

B: Does this work on the daemons in the army.... my thought is NO, because the daemons do not gain <LEGION> keyword at all, so even though they are in the same army, and benefit from everything else (actually much more so than the csm do!) I do not think that the M.O.P. can effect them, even though they're Daemons because the spell specifically calls out <LEGION>. 

So as I'm reading this, if I choose to include a Master of Possession, I believe he can improve the save of Possessed and oblits only (because sigh no freaking daemon engines) if they share a <LEGION> even though they can benefit from literally nothing else that their legion gives them, other than essentially a keyword tag for this spell. 

...ie: not worth it at all to even bother including him. 

[voodoo]

My take is, it'd be the CSM units that have the <LEGION> keyword natively. Since units gain the <LEGION DISCIPLES> keyword, that's very different from just <LEGION>.

[Typhus]

CSM still get to/have to pick a LEGION, and the Daemons still cannot.

The Master of Possessions would affect Possessed, Greater Possessed, Mutilators, and Obliterators (and Daemon Princes and Daemon Engines, if you were allowed to take those). Daemonic Cavalry Lords as well, if using Legends.

[Jack Shrapnel]

Yeah that's how I was reading it, but just wanted to have other eyes look at it.

Given the zero daemon engines / princes allowed, and that Belakor himself doesn't get a <LEGION> keyword, then the MOP is definitely a pass for the list. There's just not enough for him to buff.

I'm honestly struggling to find a reason to take any CSM in a Disciples of Belakor army, beyond a unit of havocs that can be protected to be untargetable unless they're the closest unit. Seems that anything the CSM units I'm allowed to take can do, daemons can just do better.

[Typhus]

Havocs really benefit from Disciples of Be'lakor, as mentioned.

A unit of Cultists to be able to lean into Tide of Traitors is still a solid option.

The Master of Executions is also a cute counter-charge threat, and a way to proc the stratagems which require the presence of a nearby CSM unit.

...That's about it. Without any Legion synergies, this really is an Army of Renown for Daemons.