@baukepost Trying out all of these suggestions so thanks everyone! Though I have a couple questions for you Bauke:
You say to paint a mask in texture paint mode and use it as the mix factor between the blood and the brick, what node(s) would I go about to do this? I’d assume something related to alphas but I’m not knowledgeable on that.
When you say to make a simple blood shader, do you mean to simply use a ColourRamp node to get the light and dark reds? If so, and being suggested to make the texture paint simply white, does that make my blood image texture useless? Or should I make that white in Krita or something and then stencil it on to where I want?
Thanks to you all again!