If you have resistance there is the blood thing that spreads out underneat some dead guys....
I de-pbo'd some of the resistance stuff and had a look in oxygen, and i found the blood stain one a while back, not sure what its called but surely its possible to add it ingame
? If not try and model some they should be fairly easy to make,, and you only NEED one texture!
Maybe i can do this for u if u cant? all id need is blood textures and an hour to make some good blood stains...