Chaos space marine Storylines DLC Operation/Campaign "CHAOS UNLEASH "

Anyones remember HALO 2 Arbiter campaign or Command and conquer  CDI & NOD campaign where you could see both side of the story ? Or even space marine 40k 1 Exterminatus Chaos unleash DLC that you could play as Chaos space marine ! 

It as always been great to play games where you can enjoy both side and understand their motivation and their point of view and we all know the emperor and space marine adeptus have done questionable things lol !Thats said it would be a fantastic addition to have some missions/ operation  or even small buyable DLC like 3 to 4 hours or so featuring some either on the fence chaos space marines or hardcore ones . 

Tyranids , Ai movement etc..etc.. can all be recycle to be Chaos SM foes etc.. so its not insane extra work just need good writting etc.. 

Storys that branch out into the overall story of the game or side story around it .. I would love to see that in this game not only focusing on Ultramarine even if i kinda like them ! 

Chaos unleash exterminatus COOP space marine 40k 1 

https://www.youtube.com/watch?v=V-tArYebOGg

C&C NOD and GDI missions 

https://www.youtube.com/watch?v=MCYlEtnSp04

Halo 2 arbiter mission

https://www.youtube.com/watch?v=F9-jdwR6AKU