Small one-use-only-addons are usually not a good idea in my opinion. I think its enough if you setDamage the soldier to 0.9, thus preventing him from walking or standing up and getting the blood scripts going.
Record some voice files and make him talk, begging to be put out of his misery. Maybe add some moaning and screams of pain to help the player(s) locate him on the battle field.
If you want to add more blood there's a "blod splat" found under EMPTY>OBJECTS that lets you create a puddle of blood underneath him. I think that should do the trick.
The idea to put a human "out of misery" as if he was a dog is repulsive enough as it is, without too many gory details. And voice files are more "scary" than graphics if you put some effort into them.