The others that frequent this board are much better at this than I am. Here is my shot at this.
Your color values in this are pretty close in the upper half. You have a lot of what I consider to be mid to light values. My eye really wants to find the lines around the figure and head to help me define the shapes. If the red is going to be the beginning of your blood, maybe you could try making it a darker value to offset the values around it.
After looking at this for a while, I would think that if there is going to be a considerable amount of blood on the other figures that the large face on the right would also have blood on it. My instinct would put it running along the jaw area, with a mouth like that, its the perfect shape for it.
I am a beginner at this stuff, myself. I hope that someone can come behind me and offer you some better ideas.
You have a very interesting beginning here. I am looking forward to seeing the updates and how you decide to resolve this.