Blood (with anticoagulant) works shockingly well as an art medium. It feels exactly like normal ink in a dip pen and exactly like watercolour in a brush, and works very well as a wash too if you add it to a larger volume of water. As long as you accept that blood doesn't stay bright forever and that the rusty colour is becomes is beautiful too, you are likely to have good results.
The first photo was taken immediately after she was finished being drawn. The second was taken a day later. They are not a great comparison because they were taken in different lighting, but you can see how the fresh one was more vibrantly red and the aged one is rusty in appearance.
To make it into a wash, just add water until it's the shade of kool-aid or fruit punch that you want to use.